Originally Posted by charmedquark
Because of some issues that Brian and I had been having, I was uncomfortable with Brian doing one particular thing with other girlfriend that particular evening.
This needs to be your focus though, really. Him being dodgy is its own strange issue but that shouldn't distract you from dealing with what's actually going on.
I get that it was a temporary fix, asking him not to event her, but your insecurities (or whatever the secret is) are not his to deal with. I encourage you to own up to your issues and work them out instead of restricting his actions in service of your personal emotional deal.