Yeah, Dean's a bit different about people he sincerely cares about. For one thing, he's shyer, and more nervous. He's not used to putting things out there because he had been hurt. Furthermore, if he was still hunting and had the Apoclypse still over his head. (Almost does if they get their world back), he wouldn't even consider the possibility. Usually chalked up to anything serious just not being in the cards for him.

Dean grinned, and kissed her back, his free hand coming up to touch her cheek.

He broke away to whisper, "You're gonna have to teach some of those just so I know you're not secretly cussing me or anything." Small chuckle as he spoke that part however. That he was joking around.