Sexually frustrated?m

I love my boyfriend to death. But I just wish the sex was better. Don't get me wrong its amazing, but just as it starts feeling wonderful that's when he's already, ready to bust.... It annoys me because he always finishes first. Once he's done its like he doesn't even bother trying to finish me. I just lay there like "are you serious?" Sure I can finish myself but where the intimacy? I have no clue what to do...or what I can do.