Well. If we need to find out what he is up to, maybe that is an option. Or...we could ask him about it? All's well that ends well, and that.
Dean wasn't himself last night. Not that I know him that well when he is...but Sam is a nice guy. And I don't think Sam and Noh are a fair comparison. If he wants to be with you, then I'd judge his actions -- not the words of a demon.