My baby’s father just recently got a new girlfriend apparently they been together for months but I found out through my son who apparently has been around her before I even met her and bought him toys. I mentioned to him, to not have random bitches around our son if he’s not serious about them but he says they are. I’m super annoyed because is it not common courtesy to let the mom know about a new relationship involving my son??? He’s saying it’s not that deep because the relationship is new to ME not to them {which doesn’t even make sense}

they have been together, and my son is comfortable around her.

do i not have the right to be upset???