Dysfunctional in-Laws

My fiancée's mom and family are so dysfunctional all they do is argue curse scream and act a fool ! Is it wrong for me to tell him I don't want my baby around this type of behavior even tho it's his mom and sisters ? His mom is so ignorant ....messy and just dysfunctional. My family wasn't like this and I don't want my baby picking up any of this negativity ... Am I wrong ?