I am not well endowed hence my wife’s humiliaten meets the right guy, but what I’ve read over the years there are some humiliation basics for larger men
1.) if there exist markedly bigger ones, then yours simply in not big enough for her.
2.) it does not satisfy her enough because you are spurting quickly
3.) your member is ugly (mishapened, strong curved)
4.) you are not circumcised or she does not like how you are circumcised (low, high, tight…)
5.) you are fixed
6.) your balls do not fit the concept. They are different in size, too big, too small, the sac is too loose or tight and so on.
7.) You have a weak erection, hard to arouse or it does not stay very long
8.) Caged dicks are good victims for humiliation in general. What more does it need to proof a dick is worth mocking about its uselessness and valuenessless?
This points can be used for verbal humiliation I think.