Honestly, it's not so much a question of not getting hit on as I have an "acceptable" excuse for saying no. "I can't, I'm married," is usually taken at face value, whereas "I'm not interested," even if I can get past all the social conditioning to be polite and hedge and protect his feelings, is often taken as a sign to try harder. It's completely okay to say that I can't because my husband wouldn't like it, but not okay to say I don't want to because I wouldn't like it. Of course, part of that is that the first isn't personal, but it's still kind of enraging.