Would a guy ask about my celebrity crushes for platonic reasons? Do I (29f) need to set some boundaries with my guy friend (29m)?

So a good friend of mine (girl if it matters) moved in with a guy I used to date. (They’re not dating, just roommates) I dated him for 3 months three years ago and we remain friends but sometimes he invites me to do things that feel strange. For example he’ll invite me to get a meal and then after he’ll invite me over to his place in a seemingly off the cuff way and often once there he’ll put his arm on me/ touch me in some way and he’ll stop when asked but I feel weird that I need to ask.

He has a gf now, I am dating someone now, so I thought I was in the clear but the other night, I was over at their place and he asked who my celebrity crushes were growing up. The fact he changed the subject to that out of nowhere seemed odd to me. I’d feel weird if I learned my bf was asking such questions to a girl he used to date. When we were dating he always wanted me to describe boys in my classes that I liked when I was growing up and similar things.

Does it sound like he’s continuing flirty behavior and I need to set some boundaries or is this nothing and I should just leave it alone? Whenever he pulls something I don’t like, I usually address it in the moment but i guess I never called out the fact that he pulls something basically every time I see him and id like him to stop in general.