It's normal. Especially if he has been drinking. Not just with older men either, with men in their 20s etc aswell. It can vary between not getting it up and not being able to finish. Some men struggle more with it than others and can be really sensitive about it. It's probably not you, and it has probably happened with his other sex partners aswell. Don't let it bring you down. And yes, porn addiction can lead to erectile dysfunction, you kind of "program" your brain to orgasm when watching porn and sometimes real sex (which is much messier and less... porny) does not cut it. You can ask him about this because it can be treated.