> This is Why You Always Hire a Sitter
>  by Tatsurou
> --------------------------------------------------------------------------

> Chapter 1
> --------------------------------------------------------------------------

This is Why You Always Hire a Sitter

Yaazi sat back in her father's lab, relaxing, letting the sun from the skylight shine warmly across her chitinous carapace.  Glancing up at the clock, she groaned in frustration.  She was already bored out of her mind, and her folks had only been gone for ten minutes.

She didn't want to be resentful about her parents being gone.  She was 16, after all, and she was just fine staying home, especially now that 'home' was a single location, ever since Derpy convinced her father that he could build a secret lab in Fluttershy's shed just as easily as in Derpy's basement, and that having a single home would be better for Yaazi than constantly shuttling between two.  She especially didn't want to be resentful because, after all this time, her Mom and Dad were FINALLY going out on their first real date that wasn't a riff.  To guarantee that, all of her father's riffing friends were doing riffs, distracting all those who generally forced the riffs on him.

However, this all was slowly but surely dwindling in her mind, as she realized just how BORING housesitting was, especially when she was all alone.  Sure, she'd promised her Mom to take care of all the animals, but that was easy with her understanding with Angel.  She smirked as she remembered that deal.  Angel assisted her with her chores and didn't act like a brat with her, and she in return would never experiment with him to determine if her razor sharp fangs meant she was carnivorous.

Rising to her hooves, she wandered around the lab, looking for something to do.  She paused by the weapon locker, but shook her head.  One, it was locked with a genetic scanner matched to her father.  Two, while she could turn into her father and open it, it wasn't in her nature to cause mayhem just because she was bored.  And three, her Mom would be very disappointed in her if she broke the rules.  She shuddered, remembering the one time she had so upset her mother that she wound up - however briefly - on the receiving end of The Stare.  No way in Tartarus was she risking that again.  That was the new big rule: no misusing shape changing abilities.

She skipped right over her father's latest attempts at inventing.  Honestly, as much as she loved her father, she would never understand him.  Inventing something really required a why that went beyond 'why not'.  And she couldn't think of any for a Nyan Gun.  What was the point of zapping someone and turning their bodies into giant pop tarts that shot across the sky leaving a rainbow contrail?  For that matter, what was a pop tart, anyway?

Sighing, she flopped back into her nest/hammock.  She didn't know why, but beds had never been very comfortable for her.  Probably had something to do with being a Changeling.  However, her father had managed to craft a giant, non-sticky spider web that she found was - when covered in leaves - quite comfortable.  Beyond that, it doubled as a trampoline, since it was suspended five feet off the ground.  She didn't understand why she was so bored.  She was normally quite a bit more patient than this.  Certainly, she was more patient than her friends Apple Bloom, Sweetie Belle, and Scootaloo when it came to Cutie Marks, even if finding hers had been easier since she had an idea of what it would look like ahead of time.  ...she still wasn't sure how much physics, metaphysics, and magic was involved in all of that.  It was confusing.

However, all day today she had been...antsy.  She couldn't sit still for anything.  She'd actually changed forms no less than 37 times before lunch.  What was really strange, though, was the fact that she hadn't been all that hungry all day.  She'd eaten some fruits and veggies - being half pony had some advantage, after all - but she hadn't craved any emotional energy...even after expending so much magic.  Her Dad had been ready to stay home and figure out what was going on, but Yaazi had pushed him to go with her Mom, since they'd been planning this date for weeks.

There was a knock on the door.  Igniting her horn, she wrapped the door in her magic and swung it open.  A pale purple unicorn mare with yellow mane and eyes stood there.  Yaazi bounced happily out of her nest.  "Dinky!" she cried happily, leaping over to hug her best friend.

Dinky laughed happily, hugging her back.  "Well, I wasn't expecting such an enthusiastic welcome!  Is being on your own that bad?"  As they broke embrace, Dinky walked in, her tail swishing, drawing attention to her flank, where her Cutie Mark - a scroll filled with writing halfway torn in half - frequently drew confused glances.

Yaazi shook her head to keep herself from staring at her friend's flank.  "It is when there's nothing to do!"  She threw her hooves into the air dramatically, buzzing her wings so she fell backward onto her nest.

Dinky giggled, hopping up alongside her.  "We could always activate the systems and riff something!" she suggested happily.

Yaazi gazed at Dinky flat eyed.  "Just because riffing is your special talent, Dinky, doesn't mean the rest of us enjoy it."

Dinky nodded.  "True," she said.  "Besides, knowing our luck, the randomizer would grab some terrible lesbian clop.  That would be awkward."

Yaazi rolled onto her stomach.  "Yeah, awkward."  Noticing that this had her pressed up against her friend, Yaazi scooted back a bit, her mane rustling.

Dinky glanced over.  "What causes that?" she asked, pointing at Yaazi's rustling mane.

Yaazi glanced up.  "Well, I don't know the specifics of my biology, but...based on the emotions that usually accompany it and comparing it to what happens when ponies feel those emotions - and what happens when I feel them as a pony - it's roughly equivalent to blushing."

Dinky blinked.  "Huh.  But...why were you blushing?"

"I don't know!"  Yaazi brought a hoof down on her nest in frustration.  "I don't know anything about what makes my body tick.  Even after all this time, being half-pony half-Changeling is still pretty unique, and even what stories I've seen where it happens, very few authors bother to explore the biological aspect beyond 'it happens', so I don't even have fiction to help me explain what's going on!"  She shook her head in frustration.  "Why does everything have to be so...complicated?"

Dinky rested a hoof on her friend's shoulder.  "I don't know what to say.  Not sure how I can fix this.  I don't know how to work the medical equipment to do a diagnostic, and I can't really figure out anything without it.  Nopony really knows all that much about Changelings, even after all this time."

Yaazi sighed, lowering her head to her hooves.  "This would be so much easier if I was a pony.  One whiff would probably tell you what was going on."

Dinky glanced at her.  "Well, you could be."

Yaazi blinked.  "What do you mean?"

"Well, you're half pony.  Your pony form functions on pony biology, and from what you've said, the physical sensations mirror.  So, if you become a pony, we should be able to figure out from that what's going on with you."

Yaazi blinked.  "That's...that's actually a pretty good idea."  She tilted her head.  "Why didn't I ever think of that?  Better yet, why didn't Dad ever think of that?"

"No offense to your Dad, Yaazi, but as much of a genius as he is, I don't think it's the right kind of genius."

"What do you mean, Dinky?  What kind of genius?"

Dinky pointed to the Nyan Gun.  "The kind that makes things like that."

"Hey!  You don't even know what it is yet."

"Your Dad made it.  That means it's either totally ridiculous or dangerously destructive in the wrong hooves.  Tell me I'm wrong."

Yaazi glanced away.  "Alright.  It is...definitely one of those."  She shook her head.  "Well, let's give your idea a shot."  Focusing, she triggered her transformation to her pony form.

The color of her chitin became the color of her coat.  Her mane remained the same as before but longer, and mirrored by her tail.  The shape of her eyes changed, but their color remained the same.  She glanced at herself in the mirror.  There stop a black coated unicorn mare with a sea green mane, tail, and eyes.  Her Cutie Mark was a purple shield with a circle of green stars.  It symbolized her special talent: using her Changeling magic to protect others.

After her body adjusted to the change internally, she felt the new physical sensation.  Her internal temperature had risen sharply.  She still felt as antsy as before, but now it almost felt like there was a fire under her skin, trying to get out.

"Well?" Dinky asked.  "Any idea what's going on?"

Yaazi turned and her eyes fell on Dinky.  Her heartbeat increased dramatically, her breathing became more rapid, she began to sweat-

Yaazi reversed her transformation.  "Well...I've certainly read enough fics to know what those sensations mean," she said, her mane rustling like mad now.

Dinky blinked.  "What do you mean?"

Yaazi tried to change the subject.  "You know how when Dad said we'd remember riffing, but not the riffs themselves except while we were aged up?  Well, once I hit the age I was at aged up naturally, I remembered all of it."

Dinky blinked.  "I know that.  It happened to me, too.  I still turn into a filly whenever your Dad snaps his fingers."

"I thought he'd fixed that!" Yaazi said, shocked.

"Nope.  But that's besides the point.  What do the sensations mean?"

Yaazi sighed.  "Well, if I'm interpreting them right...I'm in heat."

Dinky hissed in sympathy.  "Oh, yeah, the first one's tough."

Yaazi blinked.  "Huh?"

Dinky nodded.  "First time a mare goes into heat, the libido and everything else goes into overdrive as the entire system rearranges itself, shifting from filly to mare as the ovaries start producing eggs.  Tons of hormones running around, drives you right crazy.  Thankfully, after the first time, it's just a little twinge letting you know there's eggs in the womb."

"But...but I'm a CHANGELING!" Yaazi almost screamed.  "I shouldn't be going into heat!"

"Well, you're half pony.  It's probably your pony half hitting its first heat, and your Changeling side is interpreting it as best it can."  Dinky smiled as she nodded.  "This is actually pretty interesting, you know?"

"Well, what am I supposed to DO about it?" Yaazi demanded.  "This is not exactly comfortable or pleasant!"

Dinky frowned.  "Well, according to my Mom's advice, there's only two ways to deal with the urges of your first heat: resist them or satisfy them."

Yaazi blinked.  "So you're saying if I get off, these sensations will go away?"

Dinky shrugged.  "It worked for me.  It might work for you."

Yaazi sighed.  "Alright..."  She shifted her form back to her pony self.  "At least this way I have something to stimulate."  She rolled onto her back, spreading her legs to examine her marehood.  She giggled.  She knew her father hated that word, so she used it on occasion just to spark his reaction, because it was so much fun to watch.  "Let's see how I should go about it..."  She extended her hoof to her pussy, but accidentally touched it with the sharp edge of her hoof.  She hissed, wincing in pain.

"Are you okay?" Dinky asked.

"Not really, that hurt."  Yaazi shook her head.  "Those stories made it seem so easy..."

"Would you like some help?"

Yaazi turned to stare at Dinky.  "What?"

"Would.  You.  Like.  Some.  Help?"  Dinky waved her hoof.  "I've handled myself before, after all."

Yaazi blinked several times.  "Umm..."  Her mind raced.  On the one hoof, she really didn't want to have to sit through her entire heat dealing with these sensations and urges, however long that would take.  On the other hoof, her best friend was offering to help her with it.  On the third hoof, she'd read enough stories to know where this was going.  On the fourth hoof, in her present state, this didn't seem like such a bad thing.  On the next hoof...she'd run out of hooves.  "...okay."

Smiling, Dinky extended her hoof, gently placing the frog of her hoof against Yaazi's inner thigh.

"Umm...shouldn't you be touching-"  Yaazi's query was interrupted by a moan as Dinky began to stroke her thigh.  "W-wha?"

"There are more sensitive spots than just your pussy, Yaazi.  It can help to start on those."  Dinky grinned.  "For example..."  Leaning forward over her, Dinky lightly licked the tip of Yaazi's horn.

Yaazi moaned in pleasure as her eyes rolled up in her head.

Dinky smiled.  "See what I mean?"

Yaazi looked up at her oldest friend.  "Please..." she whispered.  "...teach me."

Dinky smiled.  "Alright.  Stand up."

Confused, Yaazi stood up.

Dinky walked slowly around Yaazi.  "There's a lot of areas on a mare that most don't think about in terms of sexual satisfaction.  Mom was able to tell me about most of them, since Dad's the sort to explore all possibilities."  She leaned forward.  "For example..."  Dinky gently ran her tongue along the base of Yaazi's ear.

Yaazi groaned softly in response.  "That's nice..."

Dinky continued her ministrations, touching on other areas of stimulation.  Her magic was useful here, as she was able to telekinetically stimulate various areas.  A lick to the base of the horn, blowing gently into the ear, a gentle brush across the Cutie Mark, a feather light touch at the inside of the knees, a magical tingle across the frog of all four hooves...

By the time Dinky was gently dragging the tip of her horn along Yaazi's spine, she was gasping.  "Oh god, Dinky...I...I..."

Dinky smiled.  "And something Dad taught me about Changelings...certain anatomy carries over into all changes."  Grinning, she rested her forehooves on Yaazi's back, right where she'd have flight muscles if she were a pegasus, and pressed down gently.

Yaazi screamed, a damp feeling in her hindquarters confirming her suspicion that this last had pushed her over the edge.  She collapsed onto her nest, reverting to her Changeling form as she breathed heavily.  "That...that was...but you didn't even touch my pussy!" she gasped out in pleasure and confusion.

Dinky giggled.  "That's not always necessary, you know."

As her magic restored her physical strength, Yaazi grinned.  "Really now?"  Getting quickly to her hooves, Yaazi closed her mouth around Dinky's ear, her tongue licking at the base while she sucked gently.

Dinky gasped.  "Y-Yaazi!  What are you doing?"

Yaazi smiled, stroking a hoof down the side of Dinky's face.  "Dinky, I'm a Changeling.  I don't just feed off emotions, I can sense the emotional states of others.  The better I know them, the more in depth and detailed I'm able to read them.  I've known you over a decade..."  She gently blew into Dinky's ear, then whispered, "And I could feel your lust the entire time you were playing with me."

Dinky blushed.  "W-well of course.  Did you really think I could do all that and not become aroused?"

Yaazi smiled.  "Indeed.  And after all your help, it would be churlish of me in the extreme to not return the favor."

Dinky glared at Yaazi flat eyed.  "You know how cliché that sounds?"

Yaazi shrugged her shoulders.  "Well, better that cliché than the one you don't want to talk about."

Dinky's eyes widened.  "I-I don't know what you're talking about."

Yaazi sighed.  "Dinky...you realize trying to lie to me is an exercise in futility, right?  I know, but I wasn't going to force the issue.  It was your choice to tell me or not."  She ran her hoof across Dinky's spine.  "Until this became an issue.  If you want this to continue, you need to stop hiding and choose."

Dinky closed her eyes, blushing brightly.  "You already know, so what does it matter?" she asked.

Yaazi frowned.  "Because you need to say it."

Dinky nodded.  "I know.  ...Yaazi, you remember when Hammer dumped me because of my Mom?"

Yaazi nodded.  She remembered the unicorn colt was an amateur smith, and he and Dinky had been walking out together for six months.  Then Derpy had tried to make him feel welcome, and he'd dumped Dinky three days later.  Yaazi had been the one Dinky had come to for comfort, just like the other two times she'd been dumped.  "I remember."  Yaazi knew why Dinky came to her.  In addition to them being great friends, Yaazi didn't need to ask too many questions to figure out what was wrong.  Words were never really needed.  That, and Yaazi had rather inventive means of getting back at callous colts for hurting her friend.

Dinky cleared her throat.  "Well...it made me think.  I mean, I always come to you for comfort, and we've spent so much time together while we were growing up...repeatedly.  And...as good as I am at communicating, with you I never needed to.  You always knew, and I knew you.  Words were never needed.  And...well...after that time, I kind of realized that 'sister' was the last thing I saw you as.  But, after the things we’ve been through together, I...wasn't sure if that was something I should act on, so I...tried to hide it."

Yaazi nuzzled Dinky's neck gently, lightly nibbling on the base.  "You didn't do a very good job.  I felt the shift in your emotion when it happened.  But it wasn't my place to act on it.  Besides, I hadn't even started looking at ponies that way yet, and I'd thought you preferred colts."

Dinky snorted.  "Given my track record, I think I'm ready to try somepony completely different."  She moaned slightly as Yaazi's hoof stroked her underbelly.  "Besides, I've...seen first hoof that you can be...well, anything."

Yaazi nodded.  "True."  She trailed her tongue along Dinky's spine.  "I could, potentially, become anything you wanted me to be.  And that's part of who I am."

Dinky moaned softly.  "Yaazi...you know...you haven't told me...how you feel about this."  She began to pant.  She didn't understand.  Yaazi hadn't stimulated her nearly enough to have made her this aroused.

Yaazi smiled.  "Well, I've only just become aware of myself sexually, but...I don't really see anypony in a special way...except you.  I enjoy spending time with you more than with others.  I...don't know my own emotions well enough to know what it all means, but..."  She gently licked Dinky on her Cutie Mark, causing Dinky to gasp loudly.  "I'm certainly willing to give it a try."

Dinky smiled, desperately trying to catch her breath.  "How...how are you doing this to me?" she asked.  "This is...so intense..."

Yaazi smiled.  "I'm in tune to your emotions right now, Dinky.  I feel only you...and you feel me in return.  My own growing lust amplifies the stimulation you're experiencing."

Dinky's eyes widened.  "How...how do you know that?"

Yaazi shrugged her shoulders.  "Instinct, I think.  Certainly seems logical, given the nature of Changelings."  Leaning forward, Yaazi gently suckled on the tip of Dinky's horn.

Dinky screamed in pleasure as she reached her climax.  She fell backward slowly, laying spread out on the nest with her hooves splayed outward, panting heavily.  "W...w...wow..." she managed to gasp out.  "T...that was amazing..."

Yaazi smiled.  "Yes, it was."  Her smile became a little wicked.  "However...I did mention it was my own growing arousal that amplified the experience for you..."

Dinky looked up at her.  "...oh..."  She blushed brightly.

Yaazi sat down.  "The question is...how far do you want to take this...and how you want to take this..."

Dinky tilted her head.  "I don't understand."

Smiling, Yaazi shifted to her pony form.  "Like this..."  She shifted to her Changeling form.  "Like this..."  With a wicked grin, she gave her Changeling form a rather impressive looking dick.  "Like this..."

Dinky found her eyes fixated on the flexing phallus.  "Oh...my..."

"Is that a choice?" Yaazi asked, grinning.

Blushing brightly, Dinky nodded.

Green fire passed over Yaazi's dick, making it quite slick.  She positioned herself over her friend...and hesitated.  "Dinky...are you sure you want me to...you know..."

Dinky nodded, extending her forehooves up to rest on either side of Yaazi's neck.  "I'm sure."  She pulled Yaazi's head forward, kissing her on the lips.

Yaazi gently kissed Dinky back, wrapping her forehooves around.  Then, instinct guiding her, she gently slipped her dick into Dinky's dripping pussy.

Dinky gasped into the kiss at the penetration.  She pulled back from the kiss.  "Gently..." she whispered, wincing slightly.  "You're a little big..."

Smiling, Yaazi shrunk her dick a little to fit more comfortably inside Dinky's pussy.

Dinky smiled.  "Forgot about that..."  She closed her eyes and moaned as Yaazi began to thrust in and out of her.

For Yaazi, this was a very strange sensation.  She didn't normally have a dick in any of her forms, and hadn't become a male before, so the entire thing was new and especially sensitive.  She was enjoying it, but she knew she wouldn't be able to last as long as she wanted to.  Besides, Dinky's rising arousal was amplifying her own.

"Yaazi..." Dinky moaned out.  "It...it's so good...I'm so close..."

"Me too, Dinky..."  Yaazi clenched herself as she began to thrust faster.

As their blended arousal peaked, they screamed out together as they came together.

The door suddenly slammed open.  "Yaazi, Dinky!  Are you alri-"  There was dead silence.

Yaazi turned her head over her shoulder and her eyes went wide.  "Dad!" she said, shocked and more than a little scared just now.  All she could think of to say was, "This isn't what it looks like!"