I can't believe some of the replies on this thread.
1) I rarely give my boyfriend blow jobs. I just really, really don't like giving them. You might say this is selfish of me; I say, it would be more selfish of him to wish to gain pleasure at the same time as causing me a lot of discomfort. Luckily, he is understanding and mature about the whole thing. We have excellent communication and a very happy relationship; he realises there are more important things in life than getting oral sex. He would rather I be happy.
2) He loves giving oral sex, so he still performs on me. If he didn't want to, I would NEVER expect him to at all. But if he didn't do it out of spite, that would make him immature and also just be cutting off his nose despite his face, surely, given that he likes to do it. Indeed, I think he likes giving more than I like receiving!
3) If he were nagging/begging me for oral constantly, it would REALLY put me off all sexual activity with him and it would make me feel uncomfortable and totally disrespected. But he doesn't, so sometimes I do feel up for giving him blow jobs, and I do it then.
4) I didn't give any blow jobs at all until after I'd had sex for the first time, so it's probably down to her own nerves surrounding the subject. It doesn't make her selfish, just because he has performed on her; that was his own choice, and it's not like if you consent to receive oral you are obliged to return the favour. I feel sorry for people whose sex lives are tit for tat ...