This is weird, I've never written anything like this but I couldn't seem to find a post asking the specific question I have so I guess I have to bare myself here! I understand anything commented can only be speculation but I'd just like to hear if any men have experience with what I've encountered or a more educated guess as to what this means.

Recently I, a woman, was intimate with a man I am very attracted to and care about a lot. This was the first time anything like this had happened between us. The experience seemed to be good from my perspective, but there's something I haven't been able to figure out. For context, we are both mid 20s.

He stayed over and we were intimate that night and the next morning. Both times, he didn't finish. To my knowledge he didn't lose his erection or anything and there was nothing wrong with the sex, I thought it was great and thought he did too (was being enthusiastic, affectionate, etc). I just don't understand why he didn't finish. We were pretty drunk the night of but obviously not the next morning when we were intimate a second time. I asked him about it because I was confused and also worried I had done something wrong. He said that when he is drunk sometimes he can't finish (makes sense to me!) but that he 'chose not to' in regards to the morning sex. I didn't press for further explanation but it really only made me more confused.

I suppose my overarching question is, why would he choose to do that? Is that a normal/common thing to do? I understand the being drunk part but I've had plenty of sex in the past and the only times something like this has happened has been if something has interrupted sex or my partner loses an erection or something- I've never heard of a man choosing not to orgasm/stopping even when he still has a full erection. Was he maybe hiding the fact that he couldn't orgasm when he said he chose not to, out of being self conscious? Or something else? I completely understand that reason but right now I'm feeling like I did something wrong or he wasn't attracted to me or regrets it. Just really curious about what this could mean! We are very close friends so this situation is more anxiety inducing than if it was just some guy I found attractive. I really like him and wanted to please him.

TL;DR: My sexual partner who I care about a lot told me after our first two times having sex that he 'chose not to' orgasm, and I have no idea why and am wondering if I did something wrong or if this is something men do. What can I do about this to improve our sexual relationship if he is struggling to orgasm/communicate?

Any insight, guesses, advice, etc would be welcome! Thank you!