I have the same problem, opposite sex.
I love to please my fiance, and I naturally "go for it" because it gives me pleasure. He never has to ask, I do it often.
Well, he hates giving me oral, even though I am clean and healthy and very attractive. It's a hang up, or laziness. He's picky about food, so I guess he is just a picky eater :)
Anyway, in 6 years together I only managed to get it about 5 times, YES, 5 times, less than once per year, and that was after much cajoling.
We have many good things together and I love him, but I can't help feeling unwanted and not very attractive to him. It is my favorite thing in sex and he knows it. It is the best and most intense orgasm a woman can have.
I often fantasize about cheating on him just to get some OS. But I am not even interested in other men.
I have asked him why he doens't like to do it, and never got a straight answer (he clams up). But I should stop analyzing him and maybe just believe that book: "He's just not that into you"?
My biggest dilemma is: At 44, am I forced to spend the rest of my life without OS? Is it worth leaving a man I own a house with just because of one sex act? The rest of our sex is very nice (and he likes to cuddle).
So I can relate to you guys. It is very difficult. I wish there was a machine that emulated OS but there isn't.