Boyfriend & his ex 💔💔💔

Told boyfriends ex multiple times to stop contacting him. I even blocked her on all his social media accounts but some how tha bitch keeps finding her way back to him. So she thinks I'm jelly. Im not jelly ik my boyfriend is a fuckkn flirt at times & i dont wanna have to beat his && her ass. So what should I do ? He nor she respects me enough to leave each other alone. Im over it. We have a month old baby together. & all he says is its not that serious. It is too me if i caught yall flirting once before 😕💔💔💔 ADVICE