My wife(28yo) and her mother(47yo)

So not sure how to go about this. I found pics of my wife’s ass and pics of her feet in flip flops/crocs in her mom’s phone. Should I tell my wife? Or talk to my mother in law? I found it weird as hell at first but then it was actually kind of hot thinking about it. What do I do? I could really use some advice on this. I don’t want to cause anything.