I have a very small, tiny cock. I had never thought that my cock could compare to other men's. My wife, for years, did not ever make any negative comments or humiliate me at all. My wife, like all women, enjoys being filled when she is having sex with a man. It is great that our relationship is strong enough that she can seek out men she finds hot and be satisfied by them.
The first time I was teased about how tiny my dick is, was by a guy in a hotel one night. He was probably in the 10" range, and when I pulled my cock out, he laughed and kept making comments about how small and "useless" my cock was. My wife never joined in, but it turned me on for some reason as he fucked my wife to climax with his huge cock.
Over the years since then, we have included some element of small penis humiliation into our time with Bulls. It is a huge turn-on for many of her Bulls and makes them feel superior, making the sex hotter for my wife.
Having my wife hold another man's huge cock in one hand while holding my tiny cock between two fingers is an arousing contrast. Or, having her hold my little cock in her hand while her bull fills her always makes me cum.