Kenzie Madison and her stepbrother Brad Sterling have to share a room with a bunk bed when they visit their Aunt's house. There's lots of sexual tension between Kenzie and Brad, which freaks Brad out. He tries to express his concerns to his mom, Claudia Monet, but Claudia tells Brad that it's perfectly normal for girls Kenzie's age to be curious about sexual things. She suggests that Brad show Kenzie his dick to normalize it for her. Kenzie gets an eyeful, but Claudia won't let Kenzie touch. Then Claudia leaves, telling the kids to get settled in. They go to sleep.
Brad takes the bottom bunk. When he can't sleep that night, he asks if Kenzie is awake. She doesn't respond, so he pulls his boxers down to beat his meat. Kenzie gives him all of a few seconds to stroke it before she asks if she can watch or even help. Brad stands his ground right until Kenzie pops her tits and butt out while asking if this will help him cum. Eventually Brad starts stroking it again because his stepsis is too hot to deny. When Kenzie tries again to replace Brad's hand with hers, he lets her. Leaning in, she starts sucking him down in a BJ that Brad isn't all that interested in stopping.
Even though Kenzie takes her time, Brad still doesn't cum. She suggests it might happen faster if he fucks her as she gets on her hands and knees. Brad doesn't even argue before he shoves his dick balls deep into that wet twat. When doggy doesn't do it, Kenzie hops onto Brad's fuck stick and rides him all the way inside her hairy snatch. The bunk beds make their acrobatics much easier! By now Brad is intent on getting his stepsis off one last time as she lays on her back. He's almost ready to pop himself, but as soon as Kenzie gets wind that Brad is on the edge she wraps her arms and legs around him to hold him inside as he blows his load for a creampie. The noise of their sex has alerted Claudia, who comes barging in to yell at them for touching.