So…

Me and my FWB like to explore and experiment and we like to be rough generally.

So the other day we were literally just in her kitchen, not in sexual setting or anything. And a kitchen knife was sitting so I picked it up playfully and very lightly ran it over her back and up to the back of her neck. She got goosebumps and enjoyed the soft touch of it. Did that a few times then told her to turn around and I pulled out her boobs and proceeded to lightly run it over those, then the areoles, and then very lightly the nipples. She enjoyed this.

We spoke about it afterwards and she was like yeah i’d like to try this. So the discussion was around doing it to her bum, and doing it enough to draw blood and cause some pain and leave some marks. We spoke about me putting my initials on her etc.

Anyway, as someone who’s never done this. Is there any guidance anyone can offer, or any literal guide online to make sure I am doing it safely, using the correct type of knife, the correct pressure, on the correct place etc.