There's a difference between teasing in the bedroom and out of it. In the bedroom is sexy and fun and everyone is trying to have a good time.
Outside of the bedroom teasing about the fetish is at best misguided, and at worst an attempt to change the dynamic of what was a standard dating relationship into something more comparable to a dom/sub paid relationship but without the structure or rules to said relationship.
I am a sub who would happily suck down an attractive woman's gas, but I would not happily put up with being told constantly that I'm trash who is only good for licking her ass clean after she shits. I dont even put up with that in my porn, why would I put up with that from a bedpartner? especially outside of the bedroom?
I get what you're trying to argue, a woman even willing to try the fetish is rare and should be treasured. But its not so rare that he should let it eat away at his self esteem .