I watched The Lighthouse with my dad a few years ago and I think that was the most awkward movie watching situation I've been in. We decided to watch it because it had Willem Dafoe on it, a positive rating, and it was on a streaming service he had. It's not really a spoiler but the movie has multiple scenes with a focus on masturbation. Neither of us turned it off because we kept assuming that was the last of it and we would have had to get up for the remote.
If it counts, my brother put an anime movie on for the family to watch. He'd never seen it before, and watching the tentacle rape of a schoolgirl scene was kinda awkward.
I feel like that's a lot like the observer effect in physics where as soon as someone walks in you watching anime all the weird stuff happens. Like when a friend I was hanging out with decided to watch A Sister's All You Need and we had to sit through the first scene of the first episode together.
I can't imagine watching an anime movie with my parents.