My boyfriend is always disappointed when I don't orgasm, or when he orgasms too "quickly" because he thinks that both are "unfair". That is, he wishes it were as "quick"/"easy" for women to orgasm, in general, as it is for men. I'm sure the reasons vary from men to men. My boyfriend just feels bad when he gets to orgasm, and I don't (because the converse is significantly rarer).

So he always tries to get me to come, and he's far more enthusiastic about this than I am. Sometimes I just don't care enough to keep trying, but he does, and this divergence can create a bit of tension.