There are a lot of thing more humiliating or at least "as humiliating" than comparisons with cock sizes.
But sometimes "humiliation" becomes into excitation.
In my case, I love comparing myself with my wife's ex black boyfriend, because I know he is better than me in sex and it makes me excite.
During our first days of relationship, my wife avoided to compare me with him. But I didn't need a direct humiliation to understand that he was superior than me.
I' was not so experienced in sex when I met my wife. So I had some difficulties making he reach her orgasms, our first times having sex.
I was happy due I was able to make her cum, but this job took me at least half an hour fucking (and trying to not cum myself).
One night, after a difficult orgasm, I asked about it and she answered what I was feared most: "I don't know why but I'm late with you. My ex used to make me cum immediately".
It was shocking for me, but at the same time I knew she had told me the truth.
Insteaad the vast majority of men (who probably would have put their clothes on and went away in that right moment), I asked her what did she need to reach her orgasms more easily, what used to did her ex.
Our sex progressed a lot since that night!
Three months before, we were spending some days in a famous seaside city from our country (our first holidays together) and I asked her how used to do her ex to get new erections just few seconds after his orgasms.
And her answer was as shocking as the other "He had a good tool".
Those holidays were fantastic! we had sex several times by day and I couldn't avoid thinking about my wife and her ex having sex.