Mother in law purposely makes my son cry and laughs about it.

Don’t get me wrong, i have a wonderful mother in law. She lives about 1 hour away so me and my SO go visit her almost every weekend. So with that being said, she obviously doesn’t see my son as much as my own mother. Every time we get to her house, she starts baby talking my son. She’s loud, obnoxious, yells. And when she talks you could probably hear hear from a mile away. So she does this to my son, and he immediately starts crying. She laughs so hard and once he stops crying she does it again. Like it seriously enrages me and makes me so uncomfortable and upset. I don’t tell her anything because i don’t have the nerve or strength to do so. My hubby is standing there watching her do this every time and laughs but tells her not to do it. She does anyways. I don’t even wanna go anymore to see her cause just her doing this every time makes me angry.

What are your guys thoughts on this?