Good morning from Texas! My family set-up is: my father, my mother (his wife), his “main” girlfriend and 2 “secondary” girlfriends which get changed usually every 2-3 years. Yes, we all live together in the same house - though it’s a big house - so it doesn’t feel crowded. It’s not a religious thing at all, we’re atheists.
No. I never mentioned it out of the blue in public, cause to me it was just my normal, so I didn’t feel the need to. But when people found out about it, they reacted mostly just with curiosity & surprise. Some people were judgy, but I never had someone be outright hostile about it.