I don’t know if it’s a modern idea or European idea of having privacy when having relations but the idea of living in large family units trying to be intimate with a partner sounds rather uncomfortable to me and I’m just trying to gain an understanding as how romantic/sexual relationships would work in those settings.
While you're waiting for a newer answer, here's an old comment by u/Muskwatch on a thread about sexual privacy in old-style one-room homes which specifically addresses historical living situations for other American Indian peoples.