Love her but not her spouse
I have a relative, Cathy, with whom I am very, very close but I have never really connected with her spouse, nor have our other family members. Cathy is a very successful woman and both she and her husband are well educated and productive. They are both a little eccentric which is positive and creative. She can dial back the eccentricities to be appropriate to various social expectations in the business world and in social situations, such as how to dress and appropriate manners and things of that nature. Her husband insists on "being himself", which consists of being nice and considerate of other people for the most part, but one area in which I feel he's very inconsiderate is that he refuses to dress in a presentable manner, or to pay any attentio to table manners when he is with the rest of us. He is an embarrassment in public, and unpleasant to eat with because his appearance and manners are gross.
Cathy wants the rest of us to accept him, no strings, regardless of whether he continues these behaviors or not. I've told her I accept him as a person but do not like these behaviors and likely never will, so his insistence on continuing them stands in the way of our becoming closer than we are (he and I, not Cathy and I). I've also told her that I don't feel it is important how close he and I are as long as he meets with her needs and expectations. She said that I hurt his feelings by disapproving of his appearance and manners.
I think her view, and his, is sophomoric about this. I think he is old enough (in his 50s) to know that appearance does matter in social relationships, as do table manners, and if he wants to social relationships to improve, he needs to up his game and literally clean up his act. This has set off quite a firestorm and short of telling her that his appearance and behavior are fine, which I simply can't honestly do, I see no way to smooth her feathers. Insight? Thoughts? Ideas?