Came up with this one on the fly when outside smoking a cigarette at a club. A girl walks up to me and asks for a smoke. I respond by giving her a big smile and saying "I can't just give you one, you have to flirt with me a little first." Worked well, got a k-close. Her friend was not impressed however, she came across the patio and dragged her away.

A few times using that line I've had middling success, it started up some banter but the girl would leave after she was done with her smoke.

One time it went over not at all, with the girl responding "Mmmm, not worth it."

Thoughts about this line? Any failure for myself so far could be attributed to not building enough attraction or incongruence.

TL;DR When asked for a cigarette I respond, "I can't just give you one, you have to flirt with me a little first."