pil's were just visiting ( for 10 days) and I lost track of the times FIL came into my bedroom. He normally has a problem with boundaries, and after being with dh for 15 years, i am used to it.
Either I was in there, or the dc's were, so to my knowledge he doesn't go in there alone, he doesn't snoop around, he just talks to whoever is in there.
But I would never go into another adults bedroom - we stayed at pil's house for six weeks and I don't think I ever went in their bedroom.
AIBU to think you should respect some spaces in other people's houses? Or is this normal behavior? and no , I didn't confront him.