How to Do It She has no idea. Photo illustration by Slate. Photo by Angela Pesta/Getty Images Plus. How to Do It is Slate’s sex advice column.  Have a question?  Send it to Stoya and Rich here.  It’s anonymous! Dear How to Do It, I’ve always thought of myself as a vanilla guy. But last year I discovered a kink I didn’t know I had, and I don’t know how to talk to my girlfriend about it. Last summer, she fell off her bike. She was very embarrassed but eventually asked me to help her while she recovered. She needed help shaving so she didn’t have to bend or twist while she was recovering. The first time I did it, I realized I was really into it. I feel bad about why it feels hot. It’s not that I care about body hair or not. It’s that her embarrassment is sexy, being in charge of this part of her appearance is sexy, and also a razor is sharp, so it’s intimate and trusting. It’s controlling her, but in a safe, harmless way that helps her with something she needs but makes her embarrassed.…