Author's Note

Due to the word-limit constraints, this chapter was not part of the original contest , and was added after judging was completed.

Bonding (Post-Contest Bonus Chapter)

“Where did you learn that lullaby?”

Bay Singer did the best imitation of a shrug that he could muster as he lay with Rainbow Dash on her childhood bed. It was a good size for a teenage filly, but not so much an adult stallion and his mare. They were spooning more out of necessity than anything else, not that either of them would complain about it.

“My mom would sing it to herself sometimes. When she was stressed out. I think she wanted you to hear it.”

“My great-grandfather wrote that song,” Rainbow reminisced. “He wrote it for my grandmother, who passed it on to my father. But I’ve never found anypony else who knew it. It was a family thing.”

Bay hugged her close. “I am family,” he whispered in her ear. “If… If Blaze really was my dad… maybe he passed it to my mom somehow.”

Rainbow lay there in silence for several moments. “Your mom really was my biggest fan.”

Bay nodded. “I know. But I wish she hadn’t been.” Rainbow laughed - a very unnatural, bitter laugh and Bay couldn’t understand why. “What’s so funny?”

“I always said my mom was my biggest fan… I didn’t know how wrong I was. And somehow, I was still right.”

Bay frowned. “I understand what you’re getting at. This whole thing is just strange. I can’t believe you’re my sister.”

“And you’re my brother,” Rainbow replied simply. “And I love you.”

They snuggled into each other again.

“Hey, Bay?”

“Yeah?”

“I’m your sister… Don’t you feel like this is wrong?”

He hadn’t thought too hard about it. He’d already loved - and made love - to her so much that it barely even registered as a component of their relationship. Up until just a few hours ago, it hadn't been a component at all. “Seems completely irrelevant to me.”

“Yeah...” Rainbow tucked herself in closer into him. As she moved, her tail flicked, brushing against his sheathe. He didn’t know if it was intentional or not, but it had an effect.

Her head tilted back and she peered up at him, scowling. “Really? An erection? Now?” Probably not.

He smiled awkwardly. “I’m in bed with an attractive mare that I love dearly, and will be the mother of my foals. What do you expect?”

“My parents are just across the hall.”

“Technically, they’re not,” he reminded her. “Besides, your brother would probably see us going at it before they would.”

She blushed so fiercely that he could make it out even in the dim moonlight. “I don’t think that makes it any better.”

Despite his arousal, he made no move to continue. Neither did she.

“Foals, huh?” Rainbow mused. “You want more? Even knowing what we know now?”

It would never stop him. He loved her. “I told you, Dashie,” he said, kissing her on the forehead. “It’s irrelevant. It wouldn’t matter if you were my own grandmother. ”

Rainbow grimaned. “Even if I was that old?”

“Well, you’re not that old. But I think I’d still love you and want to sire more children with you.”

“Grandma probably can’t have more kids.” Rainbow stretched out, forcing him to release her from his embrace. “It’s too bad, really.”

“Huh?”

“You’re talking about having more foals, but we have to wait for the first before we make another,” she said, facing him as she curled back into his embrace again.

“Ah.”

Her hoof slowly curled its way up his chest. “Do you want to roleplay it anyway?”

Roleplay… making another foal? Oh.

Rainbow pressed herself firmly against Bay, his growing shaft nestled between her swelling teats. Her nipples rubbed against his thighs as she rocked against him, sending electric tingles up her spine. A damp heat radiated from her nether regions - a thirst that desperately needed to be quenched.

“I thought you didn’t want to risk your parents…?” Bay wondered.

She pressed against him harder, gyrating against him and rubbing her teats up and down his cock. “What parents?” she asked innocently. “I’m more concerned about my brother.” A little part of her hoped he would cum all over her belly, but the desire to be filled overpowered that by a significant margin.

He grasped her shoulders and pulled her small frame down and inward, increasing the pressure from his turgid stallionhood against the cleavage of her teats. The tip rubbed against the thin fur of her lower belly as he began slowly thrusting against her. A low moan of pleasure purred from his throat.

After a few thrusts, he looked down into her eyes. She smiled back up at him. “You mean the brother who is fucking your teats like a cheap whore?” he asked.

“No,” Rainbow shook her head, grinding her nipples into him. “I’m not a whore if I’m giving it away, brother.” It was so fun to tease him.

Bay frowned, lifting Rainbow up and away from his stallionhood, and then lowered the entrance to her honeypot against his oozing tip. “I think I’ll just have to fuck some sense into my slut sister, then.”

Oh Goddess, yes please!

His hooves pulled her down as his cockhead split her pussy in half, burying itself deep within her in a single thrust. “Ah!” Rainbow cried out. She leaned forward and tried to grasp him tight, but her hooves slipped against his feathered back.

“Such a cocktease,” Bay growled. “Stupid, sexy…Mmmfff.” He began moving his hips in earnest, and Rainbow gasped a little gasp with each of his thrusts. His medial ring touched her madly winking clit with each entry, a new sensation that was driving her completely wild.

He pulled back and slammed into her again deeply before stopping. She could feel the tip of his cock pressing against her cervix. “Hah…” she breathed, having a momentary respite from the onslaught of his love.

She didn’t have long to breathe, though, as he bent his neck down and seized her lips in his, his tongue exploring the depths of her maw. She wrestled his tongue with her own, pressing up into his kiss. This was perfect.

Her hooves moved to the back of his head, holding him down as their kiss became increasingly sloppy. He could no longer thrust effectively with this posture, but it didn’t stop her from grinding herself against him.

“I love you,” she whispered, breathless and gasping from the prolonged kiss. “I don’t care who sees us. I don’t care who hears us. Please, don’t leave me wanting, and just fuck me.”

He slowly pressed into her again, and another moan - still girly, but not from Rainbow - drifted on the air. Her parents must have started their own play. She idly wondered if her first few moans hadn’t started that, too.

The sound of Windy’s voice as Bay buried himself into Rainbow’s snatch set off a wild idea. He’d fucked her so hard that her mother felt it.

That thought was hotter than anything he could imagine. He stayed still for a moment, buried inside a mewling, desperate Rainbow Dash, and listened closely to the tempo across the hall.

And then he began slowly thrusting into her, trying to match his pace to the errant gasps and squeaks of Windy’s voice. Confident that he’d found the right rhythm, he began to thrust. No faster, no slower, but deeper and more forceful.

Rainbow’s squeals increased in volume, and soon both mares were singing an impromptu duet of blissful pleasure. She seemed to be really getting into it, too, as her canal squeezed down on him desperately every time he pulled back.

“Oh, my little girl’s voice is so hot,” Bow cried out across the hall. Bay couldn’t agree more as he continued thrusting away into the quivering mess that was Rainbow.

“Yes, fill me up Daddy!” Windy cried. Oh, goddess, yes.

The noise Rainbow made between her moans of pleasure was strangled and incoherent. He wasn’t sure if she was laughing or crying, but she continued to thrust herself back against him.

“I’m coming!” Bow shouted. Bay was getting close too.

Fluid gushed around Bay’s cock as Rainbow squealed loudly, thrashing and convulsing against the bed. Random bursts of syllables escaped from her lips, clearly pleasurable but lacking any sense of coherence.

He buried himself inside of Rainbow, and his cock throbbed as he reached his peak inside her seizing pussy.

“Yes! Fill up my ass, Bow!”

Rainbow froze. Bay froze, too, still mid-climax.

“Oh, that was great, Windy...”

And then, still covered in their fluids, Bay collapsed onto Rainbow as they both devolved into a fit of giggles.