Marcus' hands came up between them, pushing roughly against Isaac, shoving him in one direction while Marcus took another step away, starting to circle back towards the door. "S'exactly it," he snarled. "You're being a fucking idiot and throwing it away. M'not going to let you use me to destroy your fucking life. She finds out, you resent me for fucking it up. S'not worth it. And s'not what I want."
That last was absolutely true, but it didn't come out the way Marcus meant it. None of this was what he wanted. He didn't want to let go of Isaac, but he didn't want to be the fucking dirty little secret with a quick fucking shag and Isaac slipping out to go back and sleep with Lavender. "Just fuck off, Isaac. It's over and done and deal with it. You just can't fucking believe m'telling you no."