jack

It's better as a cartoon: http://arloandjanis.com/discussion1.htm but transcribed below for people who don't like links. Click the cartoon, rinse, and repeat to view the set.

W: If you really loved me---
M: Whoa! Stop right there. You always say that. "If I really loved you" I'd do this or that. Which, of course, I haven't. Is that actually what you think? That I don't love you?
W: Well, no...
M: Aha! My point!