MIL called my 2 yr old a SOB

Me

Happy thanksgiving! We hardly see my MIL. My mom babysits FT for us while we wfh. MIL visits and called my son who adores her and she said come here you SOB. I confronted her and said I don’t like that you called him that. She said it’s a cultural thing, I’m like no. You call a strangers kid that and it will be an issue. Eye roll