Maybe, instead of the passive / aggressive bullshit that I suspect your '[lying] there mak[ing] smart/sarcastic comments' involves, you should just say something like 'this isn't working for me, go home / I'm going home'.
Just a thought.
I have said that before, and it worked. With one of my ex's, he asked me what I thought after we had sex and I told him "it wasn't what i expected...." and he said "WHAT!?" So clearly its not that easy to just come right out with it. We were at my place and after that he left, but still believed he could do better the next time around (we were also dating btw). I couldn't just come out in the beginning and say "we cant be together if you have a small cock" because 99.9% of the time, he's gonna say he's the man anyway. One time a guy told me he had a 12 inch for me, but when I eventually saw it, it was much much smaller than that. And he wore really baggy jeans so I couldn't see a bulge or anything. During that time, I wasn't seeking a huge cock anyway, but eventually if we had sex I'd at least want it to be good you know.