AITAH for not wanting to get married until he makes me finish?

My boyfriend and I are in our mid 20s and have been dating for almost two and a half years. We’ve talked openly about marriage throughout the relationship, and recently he mentioned proposing within the next year. I love virtually every aspect of our relationship and want to marry him as well, but part of me is hesitant to take that step until I’m certain we’re sexually compatible.

In the time we’ve been dating, he’s never made me finish. I’m attracted to him, and I enjoy sex with him, but it’s just never happened. I recognize that I take a long time to get there myself, so most of the time I’m not even trying to finish during sex. I don’t totally blame him for this, and honestly I think it may be a personal issue with me. But part of me wonders if it’s a matter of sexual compatibility too. This is both of our first long-term relationships. Sometimes I wonder if it would be different under other circumstances, even with another partner.

Normally, I’d be willing to discuss anything with him, but part of me feels like a giant AH whenever I think of bringing it up. It feels shallow and wrong to even insinuate that I’m curious about sex with other people. Is it normal to have this kind of reservation before marriage? AITAH for not wanting to get married now for this reason?

EDIT: To be clear, **I’ve communicated to my boyfriend about my difficulties reaching orgasm with him before. I will continue to do so. My issue is not about feeling uncomfortable broaching the subject with him, but rather feeling guilty that it might be treated like a “prerequisite” for marriage or an ultimatum to him.