Nimbus Burst took a deep breath as he slipped out onto the balcony of his rooms at the Crystal Empire. The dusky pink pegasus shook his black mane out, enjoying the feel of the wind through his fur and feathers. From the railing, he looked around, checking the neighboring balconies and windows for any signs that guards were watching the walls of the castle. Seeing that the coast was clear, he hopped up and flared his wings, dropping off the balcony to build up speed. He dove for a few floors, then tipped his wings and circled upwards, catching a thermal near the kitchens to carry him up to the balcony three floors higher. He touched down quietly, flapping his wings to avoid making any noise as his hooves contacted the crystal floor.

“Hey,” Flurry Heart smiled out at him from her bed. “I had a feeling you’d come up here.”

The teenaged alicorn’s horn glowed, and she flipped back her blankets, stretching out languidly on her bed. Her half-brother held a wingtip to his lip to shush her, slipping into her room and closing the windows behind him.

“Can you blame me?” Nimibus asked her, sliding into the bed next to her, slipping between her forelegs as she laid the blankets back over them.

“Mom and Dad would be so pissed if they knew,” Flurry teased him. “Especially with the Duchess of Maretonia and her daughter arriving for their visit tomorrow?”

Nimbus snorted, nuzzling his half-sister’s neck and inhaling the crisp scent of her manewash.

“The Marquessa can stay home, for all I care. You’re lucky you’re the Princess; Mom’s willing to let you find somepony for yourself.” He sighed as Flurry wrapped him in her wings.

“You already know she won’t approve of the pony I found,” Flurry pointed out, kissing his muzzle lightly. He was younger than her, but had inherited his mother’s stature, leaving the two ponies the same size despite Flurry’s alicorn status.

“So tell your Dad first,” Nimbus murmured as he kissed her back. “He won’t have any problems thinking I’m not family.”

“Nimbus! Don’t do this to yourself!” Flurry scowled at him. “They don’t hate you, it’s just… it’s complicated, especially for them. And they don’t bring it up that often.”

“They don’t have to. I just wish… I wish they’d see me, instead of him. Maybe then they wouldn’t want to get rid of me so bad.”

“I won’t let them,” Flurry promised him. “I’ve already been talking to some of the staff about it… they don’t all think that you’re just His foal. Some of them even like you!” She smiled, nuzzling his neck gently.

“Hopefully just not as much as I do,” she murmured into his soft throat-fur.

“Mmm… and how much is that?” He tipped his head back, exposing his throat to her tender nips and licks.

“Roll over and I’ll sh-ow!” Flurry yelped as she pricked a hoof on something hidden in Nimbus’ wing. “Nimbus! Seriously, are you still carrying those stupid things!”

The dark-furred pegasus cringed, fluffing out his wing and dropping a concealed blade, shifting his weight to drop one from his other wing as well.

“I don’t have magic if somepony tries something, Sis. You might have found the staff that like me, but a lot of crystal ponies know damned well who sired me and have a couple centuries of hard feelings against him to work out on *somepony*.”

Flurry picked up the two in her magic and teleported them away with a sigh.

“Nopony’s going to try anything, Nimbus. Even if they would outside, they wouldn’t do it here. You know they’d never get past me; I'd do anything to keep you safe. Now… where were we?”

“I think you were about to show me how much you like me?” He asked as he rolled onto his back.

“Mm-mm - other way on top, lover,” Flurry grinned, licking her lips. Nimbus did as he was told, splaying his wings out

He let himself relax as Flurry started preening his wings, her lips and teeth tugging feathers into alignment, pulling loose ones free to be cleaned up in the morning. She massaged his back with her hooves, standing over him and working out the tension that years of being “Sombra’s bastard” before “Prince of the Crystal Empire” put into him. She loved the little squeaks and moans he made as she worked him over, finding the knots and easing them out of his muscles, the way he squirmed under her hooves and gradually relaxed into a happy puddle of teenaged pony.

The way he tensed up afterwards, when she reached down with her magic to give his sheath and balls a light squeeze, was particularly delicious.

“Mmm… is this for me?” She crooned into his ear, gently playing with his sheath to coax his mottled black shaft into the open. “Naughty colt, getting so hard for your big sis!”

“Half-sis,” Nimbus mumbled lazily, tucking his wings in and rolling onto his back beneath her. “Not really any worse than if we were cousins, remember?” He wrapped his forehooves around her neck, pulling her down to kiss her tenderly.

“Mhm… I swear, I think Uncle Sunburst wanted us to hook up when he gave us that lesson.” Flurry giggled, kissing Nimbus on the nose and rubbing her hindquarters against his stiffening cock. “Fortunately, I have that handy little spell Mom taught me, so….” Her horn glowed as she cast a spell that made her brother’s sack glow briefly, then slid down his body to lick and nuzzle at his member. "We don't need to worry about it anyway!"

Flurry slid a hoof under Nimbus' shaft, lifting the flared tip so she could take it into her mouth with a satisfied 'hmm. The teenaged colt wrapped his pattern around her horn, letting the bobbing motions of her head turn the blowjob into a hornjob for her.

She looked up at her half-brother with opal eyes, meeting his stormy grey ones and hoping he could see how much she cared. She barely remembered the months after Sombra’s brief return, just a vague impression of worry, that her parents were hurting, that something had gone terribly wrong. The first time she'd heard them fight was when Nimbus was on the way.

What she remembered most, though, was just being looking forward to having another foal in the family. She'd loved Nimbus from the moment she met him, and while what that meant had changed over the years, it had never stopped.

She just never would have thought about swallowing his cock until the last year or two, not that she regretted it in the least! It would just have been nice if he realized she cared more than just to use him to scratch an itch, so she tried to put all of that into her eyes as she bobbed up and down his cock, watching his face screw up in pleasure.

Nimbus bit back a groan, not sure if guards would be passing outside, or if they'd do anything if they heard him. He was pretty sure most of them had an idea what was going on, but were too polite to say anything.

Not that it should matter; if his mother or Shining Armor did disapprove, it would be rank hypocrisy considering what he'd caught 'Auntie Twilight' doing on a few visits. If they had anything to say about it, he always had that to throw in their faces.

Not that he'd have to worry about it much longer.

He ran a hoof through Flurry's mane, pulling her up off of his cock and kissing her hungrily. Her wings flared out as he took control, wrapping a hoof around to grope at her flanks and pushing her back, using his own wings to press up and start tipping her.

Flurry laughed as he pushed her into a roll, turning herself to pull him down on top of her.

"Feel like taking charge tonight?" She grinned up at him, blowing her bangs up out of her eyes.

"You willing to let me?" Nimbus pressed himself against her slick vulva, sliding himself up and down as her clip winked out to kiss the underside of his member.

"Take me, Prince Nimbus," Flurry murmured, leaning up to kiss him and hooking her hind hooves around his legs.

Nimbus didn't need to be told twice. He sank himself into his half-sister’s wet, waiting folds, each swallowing the other's moans as their bodies molded to each other like they were made for each other. He held still for a moment, adjusting to the intensity of Flurry’s body clinging to his, the warmth of her body pressed so close their fur blended together. When he started to thrust, it was with slow, powerful movements of his hips, taking his time to avoid blowing his load too quickly.

"Give me a tug," he told Flurry. "Want to come together tonight."

The alicorn's horn glowed a pale blue, a matching aura pulling the pegasus' twitching balls down a little as he started thrusting faster, letting his instincts take hold. He wrapped his lips around Flurry’s horn, smirking as she gasped at the sensation of his tongue tracing the groove running up its spiraled length.

"Oh buck me," Flurry moaned throatily. Her horn was longer and sharper than most unicorns her age, but it was also more sensitive. She craned her neck so her brother could fuck her on both ends at once, the lanky pegasus stretching out to do just that, gagging slightly when the tip poked at his tonsils.

His hips tensed, his balls trying to pull up and empty themselves into his sibling's hungry pushy. Instead, thanks to her magical grip, he was held on the edge of orgasm, pleasure blending with pain as his body ached to cum. He started thrusting faster, shifting his hips to slide along her clip with each thrust, suckling harder at her horn as it sputtered and flickered in his mouth. He pulled back as Flurry cried out, her horn gushing magical energy, a few of them sizzling in his mouth as her grip came undone and his own delayed orgasm spilled into her womb, a low groan rumbling up from his chest through closed lips.

Flurry flopped back onto the bed as her orgasm passed, and Nimbus snuggled up in her hooves, nestling in against her body.

"Love you, baby brother," she murmured tiredly, closing her eyes and quickly falling asleep, utterly spent.

Author's Note

Aww, isn't that sweet?

Too bad Nimbus is a bastard in more ways than one.

Reminder that chapter 3 takes a sharp left turn into not-so-nice, so take note of those content warnings.