Hot Summer Job/Tell Bree to give you a dare
"What, you don't think I would? Dare me!"
"Okay!" Bree perks up, throwing her arms around your neck and wiggling her pelvis even harder against your stomach. "I dare you to drop your boxers!"
"Wait, I didn't think you would go there..." You totally thought she'd go there.
A sly smile forms on her face. "A dare is a dare, isn't it? Unless YOU want a forfeit!"
"Alright, alright! I also play fair. But..." you bounce your sister a few times, squeezing her cute little butt a bit more, "are you going to get down?"
"I'm sure you can manage!" she teases, her cheeks gradually getting redder.
"Pfft! Fine! I'll show you..."
You slide one hand across her ass until you're palming the crack of her spread cheeks. Shifting her weight onto that hand (not that she isn't supporting herself plenty) forces her cheeks even farther apart as you cup your fingers forward, slipping your digits between your stomach and her pussy. She gasps slightly as you grip her by her sex, one of your fingers pushing lengthwise into her partially parted slit. This careful re-positioning frees up your other hand to deal with her dare.
Your boxers are still hanging off of one hip making your task that much easier. But you take your time, gently manipulating your fingers against your sister as you manipulate your waistband of your boxers. Her legs squeeze you rhythmically and she lets out a slow controlled sigh as you bob your body left and right to inch down either side of your boxers.
Eventually gravity takes hold and pulls your shorts the rest of the way off. You lift your sister a tad higher, firmly pawing her pussy in the process. She stares into your eyes intently, her face only a few inches from yours.
"There! Dare complete."
"Prove it," she commands, squeezing her legs again.
"What do you mean 'prove it'?"
"I can't see from up here." Bree briefly glances at the floor, not really trying to see anything. "Walk away so you can prove it to me."
With slight hesitation, you step out of your boxers. You take a few steps out into the living room while your finger softly slides back and forth against the front of her slit. Making a quarter turn you both look over in unison at your boxers discarded on the floor near the stairs. Bree giggles and the two of you restore eye contact.
Both of you know it but neither of you will address it. You're standing here holding your bottomless sister by her cunt and you're doing it completely naked. Bree's nubile mound hovers a short distance from your swinging cock. Of course it is swinging less and less now that it is finally awakening to the curious predicament you find yourself in. You feel yourself gradually lengthen, lifting away from your legs. You're fighting to keep yourself in check and doing a reasonable job considering, but you're far from flaccid. She has glanced down several times in an inquisitive manner since you abandoned your boxers on the carpet, but thankfully her tight leg lock and her hanging dress appear to obscure her view of your privates, as well as your view of hers. But now that you're walking around bare-ass naked you're not quite sure how to get out of this.
"Satisfied?"
She nods her head. Immediately afterward her body jerks slightly, pelvis rolling forward and arms pulling on your neck. You're not sure if that was due to your gentle stimulation or if that was Bree looking for more, but it seems she isn't satisfied after all.