We stopped in the middle of sex?

I'm posting this again because I want to hear more opinions. So back story...my bf & I have been together for over 3 years now. We only see each other 3 days out of the week, but we usually have sex every 3 days. I always am in the mood so I always want to do it. My bf on the other hand, isn't always in the mood. He's either in the mood, not in the mood, or sort of in the mood but not all the way there yet. I get this because very rarely I am sort of in the mood but not all the way. Last night we went to sleep. About an hour later maybe, I woke up to hands all on my body & him kissing me. We were both like half asleep. Than we started doing it. About 2-3 mins in he stops. Now this has happened before & we've continued to have a great sex life after. He knows I always get upset when this happens, so he starts cuddling with me & kissing me. I asked him why he stopped & he said he just wanted a quickie (but he never came). I was honestly so tired I went to sleep. This morning I asked him again & he told me he was sort of in the mood but not all the way, but he wanted to get a little too. I always overthink so I immediately think that it's me & that I don't feel good enough. He told me that's not it, that it did feel really good (he was genuine about this) but that he was just sort of in the mood but not fully...like it was a little teaser. He told me it's a good thing because it means we'll prob do it today. & since my bday is on Monday, he's been telling me that we're def doing it that day. I don't want to overthink this because he knows everything is good & would tell me if it wasn't. Does this happen to people lol???

P.S. For the lady calling him an asshole, he's not at all. He's the sweetest.