Katie Kush puts on her bikini to go hang out by the pool. Her stepbrother, Nathan Bronson, joins her quietly so he can spend a few moments checking his hot stepsis out before she notices him. Nathan tells Katie that he's going to fuck her friend, Aften Opal. They eventually make a bet that if Nathan does better than Katie on her test next week, he gets to fuck her friend. Katie agrees and adds on that for an easy bet like that she'll even watch Nathan do Aften if she loses.

The next week, Aften and Katie are hanging out in their school uniforms when Nathan lets Katie know he aced the test. He scored better, to Katie's shock. Aften wasn't in on the bet, but once the stepsibs explain it to her she's fine with it. Aften has been wanting Nathan for a while, so she makes short work of getting his dick out of his pants and starting to suck it. As Aften turns around on her hands and knees so Nathan can bang her, she tries to coax Katie into joining them. Katie is reluctant, but eventually agrees to let Aften eat her out while Nathan fucks Aften. That turns into both girls delivering a double BJ. Katie finally lets Nathan slide it into her tight twat while Afton rides her face, creating a full-on threesome.

Swapping spots with Katie, Aften links one ankle over Nathan's shoulder so he can really dive deep. Katie gets on her knees to ride Aften's mouth once again, this time sliding her own finger into her ass to double down on her pleasure. The trio is enjoying their newfound chemistry when Katie's mom, Dava Foxx, comes home. Aften doesn't want to risk getting caught, so she takes off as Katie and Nathan dive under a blanket together to hide their nudity. Katie can't keep herself from stroking Nathan's dick as they talk to her mom, who eventually takes off. Katie takes the opportunity to suck Nathan off once again and then hop onto his dick. Riding him in her nicely trimmed twat, Katie urges Nathan to cum for her. He obliges, giving her a sticky creampie. Moments later, Dava returns and busts the siblings in the act.