Hot Summer Job/Don't push it for now, but enjoy having your dick inside her like this for as long as you can get away with

You clear your throat a little and move one of your hands down the underside of her thigh, less to comfort her and more because you can. With Bree impaled on your cock - that is refusing to calm down even after exploding inside of her - it's hard to not want even more. After your hand coming out into the open you lightly grip her skinny leg and push back up under her dress. Your rub up her inner thigh, briefly brushing up against your cock and her stretched lips, before you round your palm over a single butt cheek and slip even further under her dress until coming to a rest in the small of her back, her still taught muscles firm under your touch.

"I guess... it's your turn now."

Bree looks up at you sheepishly at first. Slowly, a grin spreads across her face.

"Good!" she says, her death grip lessening. "It's only fair!"

"What's only fair?" you ask inquisitively.

"You need a harder dare! Your dare was way meaner than mine! Having to kiss my brother..."

Is she feeling alright? Did your dick give her amnesia? How is kissing worse than having your entire pubescent snatch filled with cock? But that wasn't part of the game, which is where her focus has managed to snap back to.

"I... hey! What was wrong with my kiss?"

"Nothing. It's not that. I mean, I liked it..." she pauses, glancing away from you, "but... just shuddup! I'm gonna give you a hard dare!"

You shake your head. "Fine. Do your worst."

Bree looks around the room, scrunching her face as her mind races and her pelvis starts up again. Little involuntary baby humps nearly spasm from her crotch, but this time you're feeling them from inside her. Her tight pussy gently squeezes your length as her hips rock forward. You swear her eyebrows furrow in time with each pulse. It's a blissful feeling, having your sis clench and strain herself against your penetrating cock.

"You... have to... do... jumping jacks!" she proclaims. "And you can't drop me! If you do, then you have to do a forfeit too!"

She's already wriggling around your cock with excitement.

"That's probably not a good idea," you warn.

"My idea is just fine," she insists with a smile. "I'm not that heavy. Just hold me and jump!"

You raise an eyebrow. You hope she knows what she's asking for. "Okay. Then... for how long?"

"Until I say so!" she says confidently, tucking her short hair behind one ear.

With some uncertainty, you grab her butt with both hands and pull her hips into you trying to press her crotch as tight as possible against your pelvis. You'd like to minimize your own discomfort as much as hers. Bree wraps her arms around your neck with another bright smile.

"Go on! I didn't chicken out of your dare!"

"Okay, okay, I'm doing it..."

You make a small hop and spread out your legs for your first jumping jack. Your hands never leave Bree's ass, but gravity is cruel. Despite your firm hold of her she drops down with enough force to bury another inch of your shaft into her the moment your feet find the floor. You watch her eyes bulge open in shock as you make your second hop to get back to your starting position. The vice grip her pussy has on your meat means very little since you've already lubed up her insides with your spunk, and she slides up a good two inches at the apex of your jump only to slam down another two and a half when you hit the floor again. A sharp breath is forced from Bree's body as your cock slams up into her tiny slit.

"WAIT! WAIT!"

You had no intention of continuing. You can already feel your glans punching her cervix. You pull on Bree's butt a bit harder while she struggles through a few deep breaths.

"I can do a different dare sis. It's not a big deal if you can't take it." Of course 'it' is the fully erect manhood your little sis is impaled upon. But you'd still rather be coy about it.

"No... I'm fine. You're not getting out of my dare so easy!"

Bree postures up on you, re-interlocking her legs over your butt and sliding her arms over your shoulders and around your neck until her elbows nearly are on top of each other and she can grab the back of each arm. This presses her body fully against yours and nestles her face right into the crook of your neck. Only her thin dress separates your torso from hers. She can be really stubborn when she wants to.

"I'm waiting." Her speech is muffled by your shoulder.

Squeezing her cheeks with your hands, you make as gentle of a hop as you can. It helps, but despite your consideration and her adjustments, gravity still pulls on her. A sharp breath hits your neck when Bree's weight returns to your dick. You pause, waiting for her reaction.

Bree lifts her head up, inches from your own. "Giving up already?" she goads with a weak grin.

You don't reply. There's no need to. A more forceful hop slams her onto you once more and puts her in her place. She exhales then gasps. Every shock she experiences and the sudden pressure on your dick makes your shaft throb needily. But pausing between jumps is surprisingly hard. Jumping jacks are supposed to be done with a sort of spring landing. They're also not supposed to be done with +50 pounds of weight, but you suppose that's the challenge behind her 'dare'. A few more hops brings Bree to groan, almost whimper, and tuck her face back into your neck.

This slow, tight, bucking, bouncing fuck-dare is quickly riling you up. Picking up the pace makes your jumping a bit easier and the bouncing a bit harder, both of which your body appreciates. But as you start to enjoy yourself Bree is put through her paces. Slamming down the length of your cock half knocks the wind out of her every time. Speeding up forces her to pant and gasp into your neck, her labored breaths only making you hornier.

Your hands unconsciously lift Bree higher with each jump, helping not only to slide her along more of your shaft but to cause you to slam that much harder into her when she drops. Part of you worries that you might puncture her cervix, and a much darker part of you wants to.

• WIP