Living on a maybe

Friend 1: I'm taking off, I'll see you tomorrow.

Friend 2: Okay - will you be shooting pool with us tomorrow?

F1: Maybe.

F2: I'll call you tomorrow before we go. I'll probably see you here, right? Are you coming tomorrow?

F1: I don't know, maybe.

F2: i see - you're livin on a maybe.

F1: Yeah, kind of.