I am 50/male/fit/professional. Girlfriend is 42 fit/entertainer. We both are attractive and have jealousy and insecurity issues. One issue that is tearing at us concerns her "boss" and close friend that she has known for two decades.
Background on her: she worked as a bartender in a strip club, but it was a deal breaker for me. She quit, saying our relationship was more important. She also has a social media following, and would post swimsuit pics and other sexy pics. I was uncomfortable and she stopped posting it since.
My gf is generally open and shared that her boss and close friend expressed his love for her eight years ago. He has what is supposedly an open marriage, but in reality it is an unspoken, unclear arrangement. He has slept with two other women in their working group, one of whom is married and not in an open situation. His wife does not know and it would create a mess if truly out in the open. My gf is far more attractive then him and these other women. She insists she rejected him and it caused tension. They worked to re-establish a working relationship over time. She insists that it is professional. She also provides access to her phone and puts him on speaker when he calls. I found a two year old conversation where he was pushing to work with her on a project. She eventually agreed, then SHE joked "bring a dildo." She has a crude sense of humor and has toned it down at my request. A couple weeks ago he stated he missed her but when laying in bed thinks of her as a blowup doll. On another occasion, he made a joke about the work semen. Needless to say, I find this unacceptable. I wanted to confront him. I wanted her to end this work relationship and friendship. This upset my gf as I can be controlling. She insisted that she talk to him that there be no more sexual jokes and that I simply trust her.
What is the right course of action? I want her to fade this relationship (she needs the work) and never do a private work session with him. She says that is too controlling and I should trust her to set boundaries.