Originally Posted by Seraphic
our mutual friend didn't know /from him/ that he had permission
Without having any idea what "mooching" and "macking" are, it sounds like your BF thinks the Bro Code
Would it have made a difference if the guy you "mooched" or "macked" hadn't been friends with your BF?
It's pretty common for partners to meet other partners when relationships start to get serious. In my relationships, that meeting or communication usually happens sometime after kissing and before fucking. This isn't a "permission" or an "approval" thing. It's a "hey, look, we do have an honest, open arrangement we agree to" thing.
Some relationships do use a "veto" or permission between partners. Some people demand "Don't Ask, Don't Tell." Other people have a "NO DADTs" policy.
There's a lot of difference of opinion about vetting new partners. What's important is that you set up a process with your current partner(s) that everyone agrees with, and that everyone then follows.