Good, he was rather hoping she would be reasonably well distracted. People who start kissing him and then suddenly get more interested in the reactor when clothes-things start to happen tend to be people he finds that he isn't actually all that interested in sleeping near, much less with.

"Oh, wow. Hiding that, is just... not nice." He might just let his thumb follow the curve of one of them again, now that pesky fabric's gone. If she's paying attention, she can basically just watch his eyes grow darker as he takes her in.