Sometimes when Erik is meeting with someone and is not at all worried about first impressions and bored out of his mind, he pulls what have been dubbed the “Yiddish Grandpa” routine.
He does a THICK Yiddish accents and starts ranting about his grandkids and children, with phrases like “My Tommy is dating a human. What, is he too good for a mutant?” and “My Wanda should have married that Strange fellow, we could finally have a doctor in the family” being particularly common. Yes, it is very much stereotypical and over the top, that’s the point. He does it just to see the reactions of people meeting the mighty and terrifying Magneto for the first time and seeing this parody instead.
If Charles is up to it, he joins in with this “stuffy British Grandpa” routine pretending his students and his staff are his grandkids and children and they both run with it.