Dude that sucks man. My GF now is one of those "good girls" but she doesnt mind going down on me. The thing with her is that she doesnt want me to do it to her! Can you believe that? She has no problem doing it to me, but wont let me do it to her. I guess I cant really complain, but in your case man, if your wife wants you to do it, but wont do it back, then I'm sorry man your just gonna have to start sayin "no" to her as well.