my problem is that i have a problem keeping my erection up whenever my girlfriend and I are playing with each other. So we have been talking about having sex lately, so one day, while I'm giving her oral, and im stroking myself so i get an erection, after getting hard, i put on the condom, half way putting it on i ejaculated...has this ever happened to other people? was i too nervous? or is it because it is the first time? i felt so embarrassing.