Man can't finish?

My boyfriend and I are in a ldr but we video chat almost everyday. Before he moved, we had A LOT of sex and I could make him finish, but he's the kind that takes a really long time or he gets tired before he finishes. He says he's wildly attracted to me and he loves having sex with me, eats me out and fingers me a lot too.

We were playing around over video chat, he was jerking off and I was fingering myself, and I told him I wanted to see him cum. But I could hear him clicking on his laptop. So afterwards I asked him what he was doing and he admitted he's been having a hard time finishing lately and was watching porn to try to finish while also watching me.

I'm worried I'm not enough to make him cum anymore but I guess it's hard over video chat. He said it's been hard to finish lately since he moved so he's been watching a lot of porn, but even then it's hard for him.

Am I doing something wrong? Is there something wrong with him? (I asked him once if he gets blue balls from having sex with me and not finishing and he said no).