Draco wanted to get up, stride up the stairs, grab Potter by the scruff of his precious fucking neck and throw him the hell out. But Potter had a wand, and Draco didn’t. Hermione would be furious. And then there was the fact that if Draco stood up, he’d be gracing Potter with his rather conspicuously tented trousers – Draco’s body apparently hadn’t gotten the message that playtime was over. So he erred on the side of caution and reasonableness, and stayed sitting. He did however refuse to put his shirt back on and smooth his hair – he wasn’t going to act embarrassed by what Potter had barged in on them doing.