Me and my girlfriend are in a open relationship. We are the only romantic partners in the relationship but agreed we can have casual sex with others when we feel an itch. But it’s just sex and no feelings involved with other people.

A few months ago my girlfriend broke a few boundaries with a guy. It was very hurtful but Ive forgiven her since we are both new to this and realise these mistakes will happen and I’ve made mistakes too. We have since reestablished our boundaries and have moved on.

However my girlfriend is intending to remain friends with this guy and this makes me uncomfortable. It’s a bit complicated since he is apart of her work network (one of the boundaries she broke) but not a massive part and only would see him at big work events. I don’t expect her to ignore him at these events and expect her to bump into and speak to him at these events and I’m happy with this as it is a group setting and work related. However outside of these situations I don’t feel comfortable with her being friends with him.

They have only met this year and only a few times and have not been close friend at any point. But she intends to build a genuine friendship with him.

Am I being reasonable in saying their friendship make me uncomfortable and would like her to stop being friends with him?