To give context: my partner of a year (we'll name Diane and we've been open for 5 months) has a friend (we'll name Jack) to which they have met before she met me. On occasion, Jack reaches out to me (in a group chat with the three of us) to get nudes from Diane in exchange for money, which is agreed upon beforehand. Diane and Jack talk to each other privately on occasion since they have been friends before she met me, but I'm trusting her. A rule me and Diane has is if anything turns sexual with whoever she's talking to, that there's a group chat between the three of us.

Today, Jack wanted to see Diane naked in-person for the first time later this week but I haven't met Jack yet, and I don't trust him being alone with her because of what he said in the group chat, otherwise I trust that he will do what he says he'll do. The agreement me and Diane have (for this one time) is that she will allow Jack to see her naked but they can't touch each other. Jack wants to touch her even though she doesn't want that. He will agree he won't touch her this time even though he really wants to. He offered to pay more to touch her in some way, we then agreed he can spank her one time but not to leave a mark after he asked if he can spank her 'really hard'. I'm physically disabled and I wouldn't be able to protect her if something went wrong. I suggested for her to have someone she trusts be in the area just in case. She insists she'll have it under control even though she has a shoulder injury in case it turns violent. It's a very small chance that she won't be able to defend herself so am I wrong for being worried for her safety? To add to this, Diane thinks that I'm worried too much about this situation. That last comment bothered me a bit much. I won't be able to protect her and she doesn't want to reassure me by having someone she trusts be there.