Disturbing parents in law!

I also posted this in another group. They assume we don't have sex, and my MIL would go absolutely crazy if they knew (we are both 20) but last night they were talking saying 'fuck me now, do you want to fuck' out loud when we could hear them and it's really embarrassing for my boyfriend, even though we've been together 3 years and he's never heard them talk like that before (both in their 50s) and late last night we could hear her moaning loud in the room next door. Do you think it's very disrespectful? We would never disrespect them like that and it was early hours in the morning I'm full of the flu and they woke me up after trying for about two hours to fall asleep due to a stuffy nose and a tight chest, they woke me up with all the noise and I couldn't fall back asleep for another three hours.