(The Prompt: Two or more of the Mane Six move in together.)
Spike hefted the pile of bags onto his back, and walked slowly into the library. As much as he adored the mare they belonged to, he didn't much care for her tendency to bring everything under the sun every time she went anywhere. Given the circumstances though, maybe it was understandable.
All his grumbling melted away as Rarity gave him a grateful smile. She then turned to Twilight Sparkle, and hugged her gently. "Thank you so much for letting me stay here, darling. I know it's an inconvenience for you. For both of you."
Twilight smiled and gave Rarity a gentle squeeze before letting her go. "It's no trouble at all, Rarity! After all that's happened, I'm sorry I can't do more."
Spike chose this moment to pipe up. "Yeah, don't worry, Rarity! I'm sure they'll fix the Boutique in no time!"
Twilight shot him a look, and Rarity's lip trembled for a moment, but she quickly tossed her head back defiantly. "Of course they will, Spike. Now, could you be a dear and get the rest of my bags?"
Spike saluted sharply and nearly hopped as he ran back outside. He rubbed his scales a bit, and frowned at the pile of bags still remaining. Everything smelled charred and smokey, and it was unpleasant and annoying even to a dragon. At least to a dragon that lived among ponies. That, and it reminded him of what had happened, and he didn't want to pity Rarity.
He lifted the pile of bags, carefully keeping them all balanced, and walked back inside, setting them down with the others. Rarity and Twilight were sitting at the library's table and having tea. Spike set to his work reshelving books, though each book he picked seemed to get him closer to where Twilight and Rarity were chatting.
"Thank Celestia no one was hurt. I don't know what I would have done if my sister had been in the Boutique at the time!"
Twilight smiled and hugged Rarity again. "But she wasn't; nopony was. Even Opal was at Fluttershy's. But still, losing all your designs, and dresses... We're lucky to have even salvaged what we did."
Rarity sighed into the hug, and pulled away after a moment. "Yes, well. It's certainly a terrible situation, but I.. built up Carousel Boutique from nothing before, and when it's repaired, I'll do it again."
Her smile was obviously fake, and Spike winced a bit at the sound of loss in her voice. He pretended to dust the shelf he was standing near, so that he could keep listening.
Twilight smiled apologetically. "I spoke with the builders, they don't know what started the fire, but they think it was something in the kitchen. They say it will be at least four weeks before they can repair everything."
Spike barely managed to keep himself from shouting for joy. Four weeks! An entire month with the most beautiful pony in Ponyville! It was sad that she'd lost so much of course, but he couldn't believe his own luck! He hopped down from his stool and walked over to fetch a new pile of books to shelf.
Twilight and Rarity kept speaking in friendly tones, and Spike caught the odd word here and there. Rarity offering to pay for room and board, Twilight's flat refusal, and then Rarity's gushing of appreciative thanks for the generosity of Twilight. Spike set the pile of books down and walked over to the two. "Hey! Maybe I should go get Rarity's bed set up! Is she staying up in our bedroom, Twilight?"
Twilight nodded, and Rarity reached down to hug Spike against her coat. Unlike her bags, Rarity had managed to avoid smelling like ash and char. She only smelled like herself, and a faint hint of some sort of floral perfume that left Spike in a complete daze. The few seconds the hug lasted felt both like hours and only too short anyway.
Spike quickly went upstairs as he was released, and hauled the spare bed out of storage, before dressing it with crisp, clean sheets and fluffing pillows. He was sure it wasn't as nice as Rarity's own bed had been, but Twilight thought that expensive sheets and things like that were a waste of money. As much as he loved her, Twilight Sparkle's fixation on efficiency could be kind of irritating.
He crept back down the stairs slowly. He didn't want to run around everywhere like a little kid now that Rarity was living with them. He had four weeks to show her just how manly and grown up and attractive he was. The relative quiet of his creeping around, though, allowed him to notice the now-muted tones of the conversation downstairs. He sneaked closer, trying his best to listen in.
"And he still doesn't know? Twilight, darling, how long are you going to keep this from him?"
Twilight folded her ears back guiltily. "I just don't want to hurt him! You know how he feels about you, Rarity."
Rarity sighed quietly, and hugged Twilight against her. Spike did his best to squelch the sudden jealousy he felt burning in his chest. “I certainly understand, dear, but we can't keep this secret forever. It will be easier to tell him before he finds out on his own.”
Twilight glanced up toward the stairwell, but Spike knew better than to move. She wouldn't see him in his hiding place, and she turned back to Rarity, and then leaned in and kissed her.
Spike's world stopped turning, and then crumbled into pieces.
Rarity wrapped her forelegs around Twilight, and held her close as they kissed. It was only a few moments, but it seemed to stretch on forever for Spike. Finally, Rarity pulled away, with a slight blush on her cheeks. “We simply must tell him, Twilight. I love little Spikey-wikey just as much as you do, and I refuse to hurt him any more than I have to.”
Spike didn't hear the rest of the conversation, as he sneaked quickly back up the stairs and sat down on the floor, out of sight of the treacherous mares below. Twilight... and Rarity... were together. Together together.
Suddenly the four weeks he had been looking forward to seemed like they would be a lot less pleasant. But Spike looked over to Twilight's bed, and then to Rarity's. Four weeks... that was a long time. A lot could happen in that much time, he could show Rarity just how great he was, and she would be there to see all of Twilight's panic attacks and early morning messy mane.
Four weeks was a long time. Was it long enough to steal a pony's heart?