What went wrong?

Ok so I have been going out with this guy I like since August and we spent Saturday night through Sunday night together. He's very sweet, attentive, sexy, he know's what he's doing definitely, at first everything was working just fine down there with him, trust me. We had a quick moment and then I got hungry so we went to get something to eat, when we came back, everything went downhill, he couldn't get an erection, I even gave him a HJ and a BJ, nothing. Aren't men supposed to be visual? Is he not that attracted to me? I need some feedback.