My dad and my stepmom ,they would say little things during family outings. That let me know when they were gonna fuck. So when I figured it out I started asking them if I could go to my friends house I was about 13. They would drop my younger siblings off at their grandparents after we went out to eat on the weekend. Since we didn’t share the same mom I didn’t have to stay with them . So I would ride back home with just my dad and my stepmom. So what I would do is tell them that I would be across the street at my friends,playing video games. So they would pull up drop me off at the house and they would go somewhere I never knew where but it took about 15 min. So I would run inside grab my video games and run across the street give my video games to my friend. And tell him not to go outside for no reason. I would go back home and hide in different parts of the house . They would fuck in different parts of the house ,not like one session all over the house just pick different rooms. So how I found out was I told them I was going across the street one time and I didn’t I was 13 I went inside and figured I would jackoff while I had some alone time. So there I was jacking off in my room and I heard them open the door and I got quiet. They thought I left, all of a sudden I heard my dad saying I told you you were gonna get my whip cream all over your face . And my stepmom was like you are did. And then I hear my going. Ahh yeah suck that cock, and then she say like that and he’d say yeah so any that’s pretty much me hearing my dad and my stepmom doing the deed. Depending on where I hid I could move around the house where I could watch. Since she was my mom it didn’t really bother me . I guess. Actually she was beautiful had really nice tits and ass. There a lot more but I’ll keep it short

Not my parents. But my in-laws could hear the wall banging as he was fucking my mother-law and all the noises they did

Sure. Doors are not that thick. Neither are walls. They mostly fucked when they thought he kids were asleep, but once in a while we got up early, or shortly after going to bed and you could hear them fucking. One time they forgot to close the door and I could see them. Mom's legs in the air, Dad pounding cock into her cunt, him grunting, her moaning. They fucked quite a lot. Seemed to both enjoy it.