help ???

Nicolle
I have a problem.
I'm 18 and have been with my current boyfriend for about 3 months. We've been doing some sexual things (mostly oral and fingering) but there's one problem.
He can't make me finish.
I can do it fine by myself, but when he does anything, nothing happens. It's not like he's bad at it or anything; it actually feels really good. But I just can't cum.
I've done things with two of my other past boyfriends and neither of them could either.
Does anyone else have this problem or know how to fix it? He's starting to feel really bad about himself and I don't know how to help.