Sorry, another MIL thread. I have my own history with MIL and intense weirdness, which I won't go in to.
Anyway, MIL looks after my DN (nephew) once a week. I hasten to add that we are 250 miles away so it's not something that we are involved in in any way. MIL has a big drawer full of spare clothes for DN. I have always assumed that they were provided by SIL. Anyway, something that MIL said when we were back last weekend lead me to believe that MIL routinely changes DN out of the clothes that he is sent in and in to the clothes that she has for him. And then she changes him back before he goes home. MIL's reason for this is that SIL sends him in such pristine clothes that she worries that he will ruin them. I have no idea if SIL knows about this or not. She may well do. I wouldn't dream of saying anything to her unless it came up in conversation. I guess this just adds to my list of what i consider "weird things" that my MIL does. Not weird. Just a bit controlling. ANd also perhaps my own experiences with my own children and MIL colour my opinion.
I know it's completely harmless. But isn't it just a bit, well, odd? Re-dressing your grandchild and then putting them back in their clothes ready for collection?