Justin Hunt walks in on his stepsister Avi Love hanging out with her friend Kat Monroe. Kat is totally into Justin, flirting with him while Avi just finds herself increasingly annoyed at her brother. When Avi's back is turned, Kat takes things a step further by reaching out to start stroking Justin's hardon. Avi catches Kat in the act and flips out! She kicks her friend out, then confronts Justin in the living room.
Avi may be pissed, but Justin has problems of his own. He tells Avi that he has blue balls now thanks to her cock blocking and that it's her responsibility to fix it. Avi is eventually swayed by Justin's argument, so she agrees to help him cum. She starts off with a blowjob, but Justin quickly coaxes her that just sucking his dick isn't going to get him off. Avi moves on to stroking Justin's man meat while suckling his balls. Justin still can't cum, so Avi is left with just the nuclear option.
Peeling off her shorts and thong, Avi gets on her hands and knees so Justin can bang her from behind. She thought fucking her stepbro would be weird, but in the end she totally digs it. It's not long before she has climbed on top to ride Justin's fuck stick like her own personal sex toy. She enjoys cowgirl and reverse cowgirl before falling onto her back and letting Justin bring her home before he finally pulls out to cover her in a shower of jizz.