First time mom of a perfect LO. First grandchild on both sides. Our respective parents (my LO’s grandparents) all had preferences for the names my LO would call them. 

My mother has requested she be called a specific name, GG for Grandma, last initial (Last name starts with a G). 

My SOs grandmother has always gone by a specific nickname for her grandchildren- Mimi. She has insisted that she be called GG for Great Grandma. 

I said our child will most likely call her Mimi as that is what my SO and I call her. She has corrected me multiple times stating that she will be called GG, not Mimi. 

I personally think my mother gets first dibs of her nickname and am vetoing the nickname of GG for my SO’s grandmother, and will still push my LO to call her Mimi against her wishes. 

AITA for doing this? 