It depends. Me personally, I like to hear my wifes sexual experiences as they impact ours-we can laugh about it, talk about it, I have no jealousies, she is with me. One man she was with was so big they couldn't have sex and we did laugh about it. She said his penis was like a mini baseball bat. He would dwarf mine for sure! And vast majority of men. It doesn't bother me remotely. I jokingly told her most every woman has a super cock experience. Lol, right! I think before you answer that one I would ask why he is asking you. I would never want to see anyone hurt emotionally. If it can lead to a honest conversation sexually, tell him. You can have preferences and fantasies as a woman, he may be okay with it. But find out and ask.