When I had one of my first apartments, the walls were thin and I could hear a lot of what was happening in the next apt. Now that I'm older, I hate that, but that's all I could afford at that time. My neighbor was a young man just starting his first job, so he was enthusiastic about just living life on his own. He did have a boyfriend who would come over periodically. When I heard them, I knew that I was going to have a very good evening, because they were going to have sex and his bedroom and mine were right next to each other. Well, I prepared myself and, inevitably the lovemaking would start. I felt weird, but I tried the old glass against the wall and it worked. I could hear much of what they were saying, all of the sex talk and how this and that felt. When it came to the fucking, my neighbor was the bottom and, to say the least, he was very vocal, since his boyfriend was a very physical fucker. I heard the rhythm of the bed and the screams of ecstasy from my neighbor. Of course, all this time I was jacking off and trying to hold back so we could all come together. I usually was so turned on, I came before the boyfriend, but once in a while it was pretty close. I still remember it fondly and always looked at my neighbor differently. I'm sure he knew that I could hear the fucking, but we never spoke about it. Now, if someone next door was noisy during sex, I would probably be annoyed, since it would interfere with my sleep. But back then, it was enjoyable, because it was a bit dirty, listening in on something so private.
BTW, I reciprocated by making sure I was a bit loud and talked dirty as I was getting plowed on my side of the wall, so, if he did the same thing as I did while listening to the sex sessions, he could hear my cries and then he might have as good a night as I did every time I listened to him.