Chuck freezes, lets the kiss happen before he can really figure out what it was.

He grabs a towel and dries himself off in his room, trying to gather his thoughts and his feels. Er, feelings.
It's been...nice, which is dangerous. He should probably nip Ray's sappiness in the bud before the older guy gets too attached. It's only a matter of time before they all scatter anyway, and Chuck'll be glad to see the back of him.