ED or just me?

Tristan
I'm dating a guy quite a bit older than me. He's 41 and I'm 29. For a month or so after we started Hooking up he wouldn't have sex with me. We just had sex for the first time on our last date and he couldn't keep an erection..... The sex was like 5 minutes, and I was really confused/disappointed. All he seems to want is bjs. So, if he can stay hard for oral why not sex? I'm starting to take it personal but also don't know if it could be ED. He doesn't seem to have a problem staying hard during oral, but often uses his own hand while I'm ugh.... Elsewhere lol.