Why do i go limp during oral sex?

Hey my Girlfriend keeps trying to give me a blow job and I keep refusing because whenever she gets down I go limp...and that has also happened before sex. which really sucks...is it just me being nervous and once she does it ill go hard again or what...

else??? please I need help

Well if you don't know what happens yet just try it once and see what happens you never know till you try =]

Maybe you don't like it or enjoy it

You shouldn't get embarressed if this girl really cares about you then it shouldn't matter and if that don't work think about porn or somthing =]

Is she using her teeth? Perhaps she doesn't know what dhe's doing. There are many books on the art of fellatio. Tell her to use her hand at the same time so it stimulates in a similar fashion to masturbation. Try watching a porn while she's going down. Or close your eye's and concentrate only on the sensations. I find it especially nice when a girl goes down after I'm spent as it's much more sensitive. Many men have the opposite problem, they go limp after sex and then the girl performs fellatio to get them aroused again. Good luck.

let me help you.. mmm...