Gen X here. My mother (boomer, hippie) would have friends over and they'd smoke, they'd send the friend's kid up to my room, upstairs and around the corner. Didn't matter if the door was open or closed, they were in the makeshift den (converted garage) stoned outta their gourds. I had a few girls up, and I remember one flashing me and being nervous about it. Looking back I think she was giving me a hint, somewhere between "I wanna see yours" and "come get this." But I was a dumb teenage boy and I think I just played on the Nintendo or the computer (had both in my bedroom). But yeah, had a few girls up there, and it didn't matter if we had the door open or closed, if we wanted to hook up, our parents wouldn't have known (except my bedroom was directly above the garage, though my mother would also play her records, so maybe they wouldn't have heard thumping).
Straight guy, but again, I wasn't really interested in hooking up in those days. And when I say "friend's kid" I mean boys or girls, as young as 5 or 6 and as old as 16 or 17. I was 13-15 when I lived there. If it was a little kid, I was designated the babysitter and would entertain the kid. I was pretty good at it. Only one or twice was it a girl my age. About half the time it was a boy, and about 3/4 of the time they were way too young — not that I was really into girls, or enough to try to make a move even if they were the right age. They were all, as the guy says in Fight Club about airplane neighbors, "disposable friends." Or was it "single-use"? So I never made a move on the girls my age; whether they were attractive to me or not, we just played Nintendo or computer games or looked at comic books or something.
Black Mirror had an episode about this.
Surprised it took someone this long to actually make it.
I forget the name of the episode. If you're curious, it's on Netflix, it's in season 3, and it's right before San Junipero. It was bleak AF, which is why the only happy (and arguably the best) Black Mirror episode came right after it.