I once had a summer affair with a college girl. She was 18, I was 27. She was staying with her cousin and her cousin's live-in boyfriend. On our second or third date, we were making out on the couch. She was playing with my cock and suddenly remarked, "I still can't get over how surprised I was that you're cock's so small. My cousin's boyfriend is much, much bigger." (They'd had a three-way.) Well, if i wasn't hard before, I definitely was then. After that, she 'd tease me about my size during sex. It got us both super hot.
We were at a party talking with two other couples. Her ex-boyfriend Tim joined us. He was about her age. They talked about having done drugs together. After he left, I stated how I was totally against that. She replied I was acting just like an old man. I shot back that they were both immature little kids. She pulled closer and purred "You know, Tim may be younger, but, in comparison," reaching down and giving my crotch a squeeze, "I'd have to say, actually, you're the little boy", drawing whoops from the other couples.
One Saturday afternoon, she had three of her girlfriends from school over. She made a few cracks about my having a small one, and her girlfriends burst out laughing. I gathered she'd already shared my little secret. When we were alone in the kitchen, I whispered a complaint, and she replied, "Oh, you love it!" I had to admit she was right.
We were in line for a big hit movie. We got talking to the couple in front of us. The conversation turned to a discussion of big multiplex cinemas vs small theaters. My girlfriend claimed she liked smaller theaters, and I, somewhat surprised, said I thought she only liked them big, not small. She looked me up and down, and said, "Honey, you're proof that that's not true." The other couple caught on immediately and burst out laughing.