A little info. How old are you and her, how long have you been seeing each other?

This is a common problem. First time I had sex the guy couldn't come. When I was talking to a mate in the pub a few months back he was saying he slept with a girl on holiday - four times - but couldn't come any of those times. He didnt usually have that trouble, but I think it was cos it was with somebody new.

It's most likely to be an issue of relaxation - of letting go - really feeling comfortable. When you jack off, it's a very different feeling to having sex. I guess it's a case of getting accustomed to that new feeling.

Above all you need to feel at ease! If it really troubles you, talk to her about it. Tell her your concerns. This will help

I'd say there's nothing wrong with you since you are able to have the big "o" by yourself, however, it may just ne when/where you two are hooking up with each other. Make sure you two are in a safe place where you have no worries about someone finding you. I used to have to find hidden places to alone with my x's to keep it private etc. But as I got older I stopped caring about what others thought and you know what...A lot of things got a lot better.

Good luck!