Sometimes can't ejaculate (male), and girlfriend gets annoyed
On a rare occasion, I have a hard time ejaculating during intercourse or from oral sex. I'd say once every 40 or 50 sexual experiences this happens to me. A good example is recently it was early in the morning, and I had sort of egged my girlfriend into giving me oral sex. She did for about 5 minutes, and seemed to be really into it, but I knew I wasn't going to be able to ejaculate (I felt a bit dehydrated, and I guess I can just sort of tell). It feels great, and it still feels like I'm having an orgasm, but I simply didn't ejaculate. I tell her it's OK to stop, and that it felt really good, but she flipped out. Got up, said "you never have a problem when you do it yourself," looked at me with that 'good ing job' sarcastic grin, and just stormed out of the house. Before she left, I said "it's not a problem, it still felt great, there's no need to get this mad," but she scoffed that off.
Just about every time I don't ejaculate, something to this level happens. It's so frustrating, and it makes me not want to have sex, because I can never predict when it's going to happen. I don't know what to say to her, or what to do. I'm 22, and we've been together for a year. We've got a very active sex life, but with her getting as angry as she does from this, it makes me want to stop all together.
Any advice?