erectile dysfunction

My boyfriend and I are in a serious relationship and we decided to take the next step and started having sex. the only problem is, he has a really difficult time achieving and maintaining an erection. We're lucky if we can even get him to the point of having an erection but it doesn't last long enough to even put a condom on. He doesn't do any drugs and he doesn't even drink or smoke. he doesn't respond much to any type of stimulation from me, though he tells me he can maintain an erection on his own and even reach orgasm. this really confuses me. can someone give me some answers?

[liv_long]

Maybe your guy is nervous. Has he had sex before? Are you two in an environment where there are no other causes for concern...perhaps someone walking in on the two of you.
My best guess is that he is nervous, or he may have a medical problem. He also may be too used to masterbating (masturbating) by himself, with himself. Personally, I would ask him about it and suggest he see's a doctor.
I had to suggest this to someone i once knew, turned out they had an std, curable, but still.
So ask him to see a doctor.