Growing up, I was always told that boys could come over if I leave the bedroom door open, and I see a lot with my friends that the girls would not be allowed to have boys over/in the bedroom/have the bedroom door closed or viceversa (boys with girls).
When I realized I may be gay and trans (masc), my parents were accepting and allowed me to have the door closed with girls because I was gay and still not with boys.
Then, I had a boyfriend and they said I could keep the door closed with anyone except my boyfriend.
Now, I’m nonbinary and bisexual. Would you allow your kids to close the door?
While I’m not a parent, I know a married couple who told me about giving their teen kids “the talk”, which was about STD protection and an edict to use rubbers.
But, I think you’re asking us to weigh in about your own parents’ choices, and it’s not our place to do that. They get to decide their own comfort zone. It sounds like they are reasonably enlightened and that’s the best you can hope for. It also might be that they don’t want you disengaging too much from the rest of the household when you’re at home, as opposed to trying to be controlling about your sex life.