Some girls never break the rules. Until someone teaches them how good breaking feels.

Ryan Thomas is eighteen and in love with Kelly Brook, the kind of girl who says grace before lunch and wears a cross necklace and has never missed curfew in her life. She's perfect. Untouchable. The good girl from the good family, and somehow she chose him.

Then Ryan moves into a house with Dion Clark. Dion is everything Ryan isn't. Confident. Built. The kind of guy who walks around shirtless because he knows exactly what it does to people. He goes through women like they're disposable, and he makes no apologies for it. And from the moment Kelly walks through the door, Dion decides he wants her.

Ryan tells himself Kelly would never. She's too devoted, too principled, too in love with him. When Dion starts talking about what he could do to her, Ryan laughs it off. When Dion bets he can get her into his bed, Ryan takes the bet because he knows his girlfriend better than some arrogant roommate ever could.

Except Kelly keeps coming over. And her eyes keep wandering. And the way she talks about Dion, with that sharp contempt and too many details, starts to sound less like disgust and more like a woman trying to convince herself of something that isn't true.

The night of the bet, Ryan sets up cameras. He tells himself it's to prove Dion wrong. To collect his winnings when Kelly shuts him down and walks out.

But Kelly doesn't walk out.