My partner and I had seen each other on a few dates. Cut to the chase, we were talking sex, and he mentioned he used magnum-sized condoms. I'd heard that a million times before, so I just thought, yeah right, I don't care anyway... So I go to his house, and after making out for a long time, I pull down the zipper of his jeans, and out pops this giant thing... this was me:

"I guess you weren't kidding when you said you used magnums".