Let's Party!

"Yeah, let's get out of here!" you excitedly reply, frantically pulling your sweatpants back on.

"What? You're not coming with me," Melanie rasps as she struggles to her feet while adjusting her dress. She picks up her discarded phone and purse from the floor before slipping on her heels.

"Of course I am!" You grab her by the arm and yank her to her feet. Her bare tits swing and jiggle at the sudden movement, noisily un-sticking the dried cum congealing between her cleavage. You pull her roughly behind you as the two of you scramble out of the side door and into the driveway where you're met by a pair of bright, halogen headlights. "I told you the Uber wouldn't leave. Like he can afford to miss a fare."

The driver raises an eyebrow as he sees the two of you - hilariously mismatched - climb into his backseat. "Um, Melanie?"

"Yes," she responded in an exasperated tone. As soon as you're both seated, he turns up the music and you resume groping your older sister while the car pulls backwards into the road. Melanie seems grateful for the noise and darkness - save the occasional streetlight - that hides your actions from view. Of course, you wish he could see everything. Your left hand alternates between roughly squeezing Melanie's ample tit and tweaking her nipple. Each time you rub against it, she lets out a soft whimper that only you can hear. Your right hand slowly moves up her thigh under the hem of her dress to find her bare (and wet) pussy before slowly slipping two fingers inside.

"This is gonna be a fun night," you whisper. Your normally clumsy hands are deft and nimble now and, despite herself, Melanie moans quietly while squirming in her seat. Her inner thighs, and the seat below, are soon coated with sticky, wet jism while you kiss her along the neck.

You're a little surprised by how much it turns you on to see her finally get into it and let her freak flag fly. Before you even have a chance to say anything, one of her hands instinctively reaches out to start stroking your cock over your pants. In a full make-out now, the two of you were engrossed in each other, forgetting where you were. The driver up front is engrossed in a conversation on his Bluetooth and completely misses the show in his rearview mirror.

"Fuck, David," Melanie moans in a breathy whisper. "Why do I want to suck your cock again? This is so wrong."

You break off the kiss and take your hands off her, staring into her eyes where fearful **** has been replaced by hedonistic desire. "Just shut up and suck it," you reply while grabbing the back of her neck with your nearest hand. Sweatpants slid down to your ankles by your remaining hand, you barely have to push her down as Melanie gobbles your entire cock into her throat. It's so sudden you can't help but let out a loud moan. "Fuuuuuuuuck!" Your hands clamp to the top of her head and push down.

"Hey, what the fuck is going on back there?!" So much for privacy.

"I'm getting a blowjob, what does it look like?" you sarcastically answer in a strained voice. Melanie is moving all on her own now, hungrily and noisily sucking you without a second thought. Slurping loudly, twirling her head and tongue, massaging your balls with her hands - you had never seen a woman so eager, not even in porn. What if this slut really is addicted to my cum? you think for a moment, filing it away for later.

"She's getting spit all over my fucking seats!" the driver yells, derailing your train of thought.

"Relax, dude, you're fucking with the mood," you reply with a flippant wave. The driver is clearly furious, but the ride continues anyway with a new soundtrack: Melanie's loud, exaggerated gags. GLUCK GLUG GLUMPH GLUCK GACK bounces off the steamy windows. With her head on autopilot, your hands are free to explore her body - squeezing her ass and groping her tits. Though he's incensed at the stains you're leaving in his backseat, the driver also can't help but look back and take in the show, shifting uncomfortably in his seat.

It's unclear how much time passes - you and your stepsister are off in your own quasi-incestual bubble - but soon a voice breaks through the gags. "AHEM! We're here!"

"Huh? Oh shit, really?" You hadn't even noticed the car was stopped, likely hypnotized by the repetitive bounce of Melanie's head. "Better finish up then." You grab chunks of her hair and pump with everything you have. GUCK GLUCK GLUCK GLUCK GLUCK. "Come on, slut. Get your reward. Get that fat load," you encourage her. The driver is turned around in his seat now with his phone taping the entire incident.

"UGH HERE IT COMES, SIS!" you bellow. Your body spasms and shakes as your balls finally release, ejaculating with enough **** to lift your hips from the seat. "UGH FUCK YEAH YEAH YEAH YEAH" you yell, bucking hard against Mel's face, likely bruising her vocal cords. Once you're spent, you pull the groggy head from your sopping wet crotch and slide out the door. You wait a beat and poke your head back in.

"There's a cleaning fee, or whatever?" you ask, rhetorically. The driver nods, open mouthed and staring at Melanie. "Use her mouth as long as you want, and we'll call it even, yeah?" you offer. He nearly nods his head off his neck before starting to climb into the backseat. Moments later, the car starts to shake and you can hear Melanie gagging once again.

"I told her it was gonna be a fun night..." you smirk. "Now where the hell am I?"