Hookup misshap?

Ok, so I met this guy online, and we hit it off. We both agreed on getting tested prior to hooking up since we were both just looking for that. Everything was going well, we texted and things were building up even more he even bragged about an all night experience lol. When the night came there was so much sexual tension between us, he wanted me and I wanted him. So when the time came it was good, though he didn't make me cum, but he did give me pleasure. He came and we talked a bit while on the bed afterwards. He then tried to go another round and I was all up for it, he tried for about 5 mins but then he said he couldn't, the rest of the night was just like that, him trying but then giving up, I tried too but he would get soft still after abt 5 mins, so part if the night was just us conversing. I convinced him to just sleep, he was worried he was gonna try to fuck me again lol, but he was so tired he just fell asleep within the hour, I decided to sneak out and leave him a note thanking him for the fun night.

I was just wondering, has anyone experienced this when on a hookup? It was strange, and I feel bad for him. What do you think would be a few reasons for this to happen to a guy?