Can't get off

So I've had a few sex partners and only one guy has been able to get me off. I can't get off by just having sex (is that normal?), no matter what position. I've only been able to get off if the guy eats me out. Well I've been seeing this guy and he has a really bad gag reflex and can't eat me out, so in result i cant get off. Any tips on how I can help him get me off? I've tried playing with myself while we have sex and I get close, but either it goes away or he finishes first. Please help!! It's not a big deal to me, but it really upsets him. He thinks I don't enjoy having sex with him 😩