It is also better for when Dean wakes up that he isn't wrapped around the angel, because when sober daylight hits, it's going to be...rough going. And he tries to be as quiet as possible, even as he hobbles around in a lot of discomfort in his lower region, finding discarded clothing, not even bothering with a shower or teeth brushing. He's going to try and sneak out--which is probably the stupidest idea ever, considering he's in New York City, hundreds of miles from the bunker, and Gabriel is an archangel.