Sorry for a challenging and maybe weird question.
It is something my parents engaged in a lot while I was growing up (presumably unknowingly), and it’s also a recurring point of discussion online, wherever I go.
On the internet, most people seem to regard it as very traumatic, though my own experience of it wasn’t. It was more just something that happened, and most of the time I’d be sleeping through it anyway. I also feel that any potential trauma here is mitigated by raising your child with a generally healthy knowledge of sexuality.
A common comment on the topic is that people can “just do it quietly,” but I’m inclined to think that some people do need to react very loudly to sexual stimulation.
Interested to hear what everyone else’s experiences, or views on the matter, are. EDIT: If the question interests you, here’s a guardian advice column post with extensive comments on the matter: “I can’t climax quietly and I’m worried my teenage kids will hear me.”

I personally would be at least cognizant of that. Same rules apply for parents with kids in the house as it does for people everywhere: DO NOT involve unwilling participants in your sexual activities.
The fact they don’t see anything wrong with this is somewhat disturbing. At the very least, you’d think they would make a minimum effort to mask it from their children.
They would do it at night, I’m guessing they had no idea how audible it was on the various audible occasions. So I’d say they made effort to mask it - they’re certainly not exhbitionists. Other instances I’ve read about seem far worse.