A few further thoughts, FWIW:
I would not show her face. Unless she's a trained actress, she may have difficulty mastering the expressions needed to match the dialogue. Maybe I'm prejudging her, and if so, I apologize. I just see so many vids ruined by weak acting that I think it's worth warning about. Anyway, personally, I wouldn't want my girl to be identifiable in something like this, because the Internet never forgets.
This is more a critique of other vids, and not of what you're contemplating, but one thing that wears me out is repetition. I think if I were shooting an unscripted video, I'd make a list of terms and phrases that she could refer to, keeping it off camera, and work her way through them. (How many talk vids have you seen ruined by the girl running out of words and saying "extra skin" over and over?)
Have her ask you questions, like Krymsonite. Make them personal and revealing. Most of us, I think, like to talk about our foreskins because we don't get to do it anywhere else.
