Telling me I had a big dick would be a good start
Use the fact that he has a big crank to your advantage.
Tell him that he is a little big and it hurts in certain positions since he fills your pussy so much and tell him what he could do to prevent hurting you.
That way he still gets that "I'm The Man" Ego & you get him to hit all the right spots.
I don't know about the rest of you guys but that would work for me.