What he is doing is purposefully keeping you in line by making you insecure. Maybe he is insecure himself. He is also invading the privacy of woman, objectifying women to walking breast and thinking his pleasure is more important than his self control.
He sounds like a creep actually. I am certainly he seems nice to you because you love him but he has a problem, not you. He is not a nice man he should not be around women because he can't control his actions. Did your cousin know that he examined her bra and took an interest in her breast size. If a man examined my bra I would ream his creepy azz out and never be around him again.
There is nothing wrong with having a preference for body parts however, there is something wrong with letting you know you don't measure up and touching someones intimate apparel. She did not put it there for his pleasure. He is out of control.
This is what i would do. Put a moratorium on sex and tell him he needs to go to IC and MC. let him know he is the problem not you and he needs to solve it. Let him know you have put up with it in the past but the incident with the bra shows that the problem is serious and no intension of putting up with it.
He will say the same as he has always said but keep to the script, he needs to realize he has a problem. The danger is that his behavior may escalate to doing things that are more invasive and get into legal trouble.
How do you feel about fighting fire with fire? Penis size. What ever size he, make subtle contents wondering how large random men are. If that does not shut him up, start making comments about the ideal size of a penis for women. If that does not work, pretend to check out men and asking him how large he thinks they are. Let him know you do computer searches for pics of penises.
This may carry it too far but take what you think you can do and do it. Your husband is not a good or nice man. There isn't a man on the planet that is not aware of a woman's issue about being good enough. There isn't a man who does not realize that it is inappropriate to handle a woman's underwear.
My magic wand would remove shame from sexuality for all! Anon Pink