I'm hurting him

Idk if this is even the right place to post this but I need help!

When I'm having sex with my SO doggy style it always takes me forever to have an orgasm and he can't last as long as I can (always been like that). So normally he gets off which is fine when it's during my fertile window but any other time it annoys me. I've decided recently to touch myself during sex in this position to reach an orgasm which works amazing! We had sex last week and that was the first time I came in that position with him and as soon as it happened he came too and said that I was squeezing his penis really hard when I came to the point that it hurt. I didn't believe him and started to laugh while he was still in me and he starts yelling at me to stop laughing because it felt like I was going to break his penis. He actually smacked me to make me take him serious and then I felt terrible. We just had sex in the same position and I got off and he said the same thing happened again. He has never pulled out of me so fast in his life as he did tonight. I feel really bad that I'm hurting him and don't understand why it's happening. He is very much so on the large side size wise so maybe if he's in too deep that's why it hurts when I come? We can have sex in any other position and this doesn't happen. Please someone tell me that have had this same issue and how I can fix it. It's killing me to know it hurts him that much.