I had something happen the other night that hasn't happened before and I just wanted to get some other people's comments and/or suggestions on it.
I was with my girlfriend and we were making out a lot and there was a lot of foreplay going on. When we were ready for intercourse, I was not hard.

I never got hard and we ended up going to sleep pretty frustrated. This has never happened to me before and I'm a little confused. We had sex the previous night a couple times and even earlier that day so I know everything works down there so I don't understand why this happened. She says it's OK, but it is really bothering me.
Any thoughts/comments/suggestions would be great.
Thanks!