Need advice

Next time they come around, don’t open the door.

Well it's simple stop inviting them over. Well they probably do not want to start anything and just keep quiet

For Gods sakes bro. Be the man of the house and protect your woman .

Never invite the vampires in.

Why does your cousin have this power over you ?
Why does your mother not put him straight and say if he refuses to be respectful he's no longer welcome ?

I wouldn't tolerate that kind of behaviour from anyone.
Least of all family

Stop them from coming around 🤔🤔

Stop inviting her

Stop letting them in the house. Tell them not to come over because they are rude

Set a boundary and if they can not respect that, have them removed from the property.