"I can't perform with an audience or competition. But I do have a recurring dream that (1) I was invited to join them"

What do you mean, cannot perform? You may not rise, but does this hamper using your fingers, lips and tongue as you know they should be used?

Also, would you like to be shoulder to shoulder, cheek to cheek with your son between his girlfriend´s thighs? He does not yet have the experience of what a girl´s private parts feel, where they are sensitive or painful to touch, where they produce pleasure for her... you do not have these parts either but unlike him, you´ve handled a girl´s privates before, and can tell and show him what to do and what not to do.

And you cannot perform anyway, because your private parts are too big to fit inside her. Whereas his private parts are age appropriate size for her. So how about making sure that he does not hurt her during defloration?

Anyway, if you cannot perform with audience, do you mean that two ten year old girls together would get nothing out of you? One of them would be "audience" when you concentrate on the other, and vice versa.