I think this can be normal at times. Society has people thinking that men are like light switches, can be just turned on with one touch. In all reality its not like that. Some men need certain things to get aroused for instance be touched in your inner thigh or maybe have you neck sucked on while others just look at a women and get aroused. You must look at your life and see if maybe you are stressed or preoccupied with other thoughts. Your Gf needs to understand that at times you wont be aroused when she is and vise versa. I think you are perfectly normal, don't worry about it
There are so many things that play into this. Don't worry about it. Nerves, stress, you could have been catching a cold... anything. It doesn't mean you don't want to be with her. It can mean that you are having second thoughts, but if she can usually get you aroused, I wouldn't be concerned.
oh yes, she usually can get me very aroused, but she can even do it when she is away when she goes and spends time with family..then she can just do it through web cam..is that still normal for me? I mean, when she saw that I didn't get aroused one time, she felt really bad, like she thought she wasn't good enough for me..
Perhaps your girlfriend isn't 'touching' you the way that WOULD get you aroused.
You could also have a low sex drive.
Has she ever done anything that has gotten you aroused?