Is it okay to masturbate while you're in a relationship?

I love my boyfriend with all my heart, but he doesn't really get me off. And that's okay because I still enjoy the sex! I don't need to orgasm during sex. But I enjoy getting it out somehow lol. Usually when I'm home alone I'll masturbate and get myself off but for some reason I feel guilty? Is it okay that I do this? Does anyone else in a relationship do this...?