Look, kid, I appreciate the offer but today has not been my day and I wanna drink my ass off and try to block it all out. If you were old enough to get into a bar, I might have considered it but nah.

[He doesn't want to leave the bar to go talk with some kid, he's not in a good headspace for it and he's not really sure if he can trust himself right now. He doesn't want to do something he's going to regret.]

Some other time. [It's a dismissal really. He's not chasing her up and she won't be going after him, not once Leonard gets to her.]