Originally Posted by ratbastid

Tell her.

I know. I know. You're ashamed and worried. I know. But really: this is a situation where an honest, open conversation will go a LONG way toward easing the very nerves that are causing the problems.

If you can be open enough with her to have sex with her, you can be open enough with her to tell her about this. And then if it happens, it happens, and nobody's surprised or disappointed, and the next time can be even more relaxed.