Medic was walking around the Fortress one day when he heard a whimpering sound. Confused, he followed it, only to find Chompy - who was now bigger than the truck and looked armor plated from the thickness of his metal hide - whimpering, huddled in on himself, and with a teardrop hanging from each eye. Another heart breaking whine found its way between the razor sharp teeth as Medic approached. "What's wrong, my large metal friend?" he asked, petting Chompy's side. "Feeling ill? Bit your tongue?"
Chompy shook his body, mimicking a head shake. He whined again.
Medic rubbed his chin. "I don't know how to help you. Perhaps we should ask Fluttershy-"
Chompy suddenly whined loudly, huddling in on himself.
Medic opened his mouth in an "Ah" of comprehension. He didn't need Fluttershy's ability to speak to animals to interpret that. "She yelled at you, didn't she?" he asked.
Chompy nodded, the teardrops falling to splash on the ground as sizzling acid.
Medic carefully avoided the teardrops and rubbed Chompy's side comfortingly. "It's alright, Chompy. She didn't mean it, trust me. When she calms down, she'll come back to apologize to you. She's just of that age, understand?"
Chompy tilted, barking his confusion.
Medic shook his head. "I forget you're younger than her, for all you're larger than all of us combined. She's becoming an adolescent. Her body is going through changes, and that's hard on her mind. She's going to be irritable at times, but she'll grow out of it."
Chompy barked a query, shaking himself.
Medic thought for a bit, interpreting. "Awareness of her body?" he queried. When Chompy barked confirmation, Medic continued. "Well, she's becoming a mare, and is becoming aware of herself as a mare, starting to think in certain ways. It's like what my large friend Heavy told me about the other day..."
Heavy could only stare as Fluttershy bounced and swayed to the music she was listening to, singing along her own version of the lyrics.
"Santa Heavy, an outer space convertible too, not blue
I'll wait up for you here
Santa Heavy, hurry down my chimney tonight!"
When she spoke of her chimney, she swayed her hips, her tail tantalizingly swaying over her flank in a way that mightily disturbed Heavy, since she was singing about him.
"Think of all the fun that I've missed
Think of all the fellas that I haven't kissed-"
Fluttershy kissing boys? Heavy thought to himself in shock. But she's so little!
"Next year I could be oh so good
If you'd check off my Christmas list
Boo doo bee doo"
As she wriggled her body in a manner that could possibly be classified as seductive, Heavy hid his face in his hands.
Medic shuddered as he finished describing it. "It is hard to accept our little girl becoming...sexually active, but she is of that age."
Chompy shuddered as well, then barked an inquiry.
"Her irritability?" At Chompy's nod, Medic continued. "Well, the changes her body is going through aren't exactly pleasant. It's a lot of internal rewiring, and it's making her hormones go screwy. She gets angry and frustrated easily as a result..."
Fluttershy growled under her breath. "I'm so angry, I could just scream!" Taking in a deep breath, she let out an adorably quiet scream.
"Aww!" Scout said, finding it too cute.
Grumbling, Fluttershy pulled an air horn out of her saddlebags and brought her hoof down hard on the button. After the noise died down, she sighed. "Much better," she said, walking away as Scout clung to the ceiling.
Fluttershy paced angrily into Demoman's mixing room. "I'm so frustrated, I could just kick something!" she snapped, turning around and kicking a barrel.
The barrel wiggled back and forth a tiny bit before settling back into place. Demoman breathed a sigh of relief.
Growling, Fluttershy pulled her rocket launcher and fired it at the barrel. One massive explosion later, she sighed in contentment. "Much better," she said as she walked out.
Demoman stared at the crater that remained of his lab, and the pile of ash that used to be his eyebrows.
Medic shook his head. "But don't worry, Chompy, Fluttershy will grow out of it. It'll take some time, but-"
"Daddiem! Daddiem!" Fluttershy called, sounding very frightened.
"I'll be right back," Medic said, rushing off to Fluttershy. "What's wrong, Fluttershy?"
"I...I think I might have the plague or something," she whimpered in fear.
Medic tilted his head. "That is serious. What makes you think that?"
"This weird mark appeared on my butt!" she wailed, turning to show him.
Arranged on each flank were three pink butterflies with bee stingers, arranged in a triangle.
Medic stared at this for a time, going through possibilities in his head. He knew it couldn't be a sickness, as the arrangement was too regular and mirrored too perfectly on each side. He also knew it wasn't a tattoo and a prank, because it wasn't in Fluttershy's nature to prank like this, and no one in the fortress would prank her. That only left the possibility that it was natural, but he needed to confirm that. "I need to speak with my hard hatted friend about this."
Fluttershy tilted her head in confusion. "What would Dadenji know about this?"
"Possibly everything. Come with me to the Medical Room." While he could still pick up and carry Fluttershy, she got touchy about it these days, talking about how she was a big pony and could walk or fly herself. The first time she'd said it to Heavy, he had smiled, nodded, left the room, and burst into inconsolable tears. Medic picked up his communicator. "My hard hatted friend, please meet me in my lab," he said into it.
Engineer was waiting for them when they got there. "What's the matter?" he asked.
Medic pointed to the marks on Fluttershy's flanks, then pulled Engineer off to the side. "You know more about Fluttershy than you let on," he stated. "I don't care why or how. Right now, I need to know what. Specifically, the mark that has appeared...is it natural, and if so, what is it?"
Engineer nodded. "It's her Cutie Mark, symbolizing her special talent. Given it matches her pin, I'd say it symbolizes her ability to speak to animals, and her combat training to - as Spy put it - 'float like a butterfly and sting like a bee'."
Medic nodded. Before he could say anything, Fluttershy spoke up. "Cutie Mark?" For some reason, those words seemed important to her.
Medic smiled. "It's apparently normal for your species," Medic replied.
"It appears when you reach a certain point of maturity, and discover your special talent," Engineer explained.
"What's my species like?" she asked.
Engineer frowned. "I'll...tell you later. For now, you should show everyone your Cutie Mark. It's something to be proud of and celebrate!"
Medic nodded. "Everyone to the Med Lab," he said into his communicator. As everyone arrived, Medic gestured. "Something wonderful has happened!" he told them, showing them her Cutie Mark.
Scout was the first to speak up. "She got a tattoo?"
Fluttershy shook her head. "No, it's my Cutie Mark! It shows my special talent, and shows I'm becoming a grown up-" She paused. "What's a tattoo?"
As some of the mercs got misty eyed, Soldier pulled up his sleeve to show one of his tattoos. "It's a design in ink you put on yourself to say something about yourself."
Fluttershy smiled widely. "Can I get a tattoo?"
Everyone looked at each other for a time. "Don't see why not," Soldier replied.
"Would be a bit more complicated since you have fur...but I can figure something out," Medic replied. "Why don't you draw out what you want your tattoo to be, while I figure out how to make it happen?"
Nodding, Fluttershy pulled out a piece of paper and some drawing implements. As nearly everyone gathered around her, Engineer slowly walked out of the room, heading for his own.
Once he was there, he pulled out a large book labeled Our Baby. He opened it up, revealing a complete collection of every picture the team - the family - had taken of her. As he turned the pages, he began to sing softly to himself.
Part way through the first verse of his song, he wiped the tears from his eyes as he paused on a family photo, taken at her fifth birthday. He then turned to a page of pictures of Fluttershy's combat training. Those were such happy memories.
"Where are you going, our little one, little one?" he sang then, only to be surprised as Heavy's deep, rich baritone sang the next line from behind him.
"Little dirndls and petticoats, where have you gone?" As he joined Engineer at the scrapbook, they turned to more recent pictures and continued to sing together until they turned to the last picture in the scrapbook. This was a sketch Sniper had done. It was a speculated image of a full grown Fluttershy, with a baby Pegasus gently cradled in one wing.
"Turn around and you're a young mare, with foals of your own," they concluded their song as the two fathers stared down at what would surely be their daughters bright future. As their emotions overcame them, they wrapped an arm around each other as they let their tears fall.