[So fast and sneaky! He shoots her a smile that spills over into a laugh once she mentions the percentages, but aside from that he lets her departure remain uncommented on. Most of all he's not sure how to handle this. There may be some flustering.
This isn't the first time he's in her room, and just like the previous times he doesn't poke around too much. He does take the opportunity to take a closer look, but it's still pretty casual and most of all he's just waiting for her to return. Every other time has been awkward or weird or downright tainted with a slow-burning panic, but tonight he feels oddly relaxed. Maybe he doesn't feel like he knows how to handle girls or relationships or whatever you want to call this, but he's doing a pretty good job anyway... isn't he?
She seems happy around him. That's a victory right there.]