Would you let your children know if you had a favorite if they asked?

Earlier today my SO was saying how I am my dads favorite and my brother is my moms favorite. Which in all honesty it is true. I have a younger brother and an older sister and we do all do agree to that but our parents just won't tell us, according to them they don't have a favorite. Well my SO said when the kids are older and if they all happen to ask if someone has a favorite that he will tell them. I was a bit thrown back at this ... in my opinion he shouldn't tell them who it is if he does have a favorite. I just feel it would cause hurt to the other kids like they would try their best to be his favorite, like a competition. It bothered me so bad. I told him but he. I think it's wrong, that's just my opinion 🤷‍♀️