Kevin wasn't really very rough at all, and the things they were currently doing were making it somewhat difficult to stay in character. But in a vague part of his mind, he reminded himself that it was Alec she wanted, and he got back into that mindset as much as he possibly could.
Just in time, thankfully, because she broke the kiss and gave him a moment to open his eyes, noticing the tattoo on her arm as she lifted his shirt over his head. Any vague flickers of surprise and slight fear on his face were covered by the shirt as it came off over his head, and by the time he was visible again he'd recovered, a slightly darker look in his eyes.
There was no way he could run, not now, without making it obvious that he was running from the Mark. So he did the only thing he could think of to make himself feel safer - he grabbed her wrists, fingernails digging into the soft skin as he pinned her hands against the wall, fear giving him an extra bit of aggression and dominance. He leaned in, biting down hard on her throat, and when he'd forgotten to be afraid because of the scent of her skin, let go of her wrists to get her shirt off.