My sister & her bf

Ok ladies. I need your opinion. So my sister and I’s bedrooms are next to each other so we share a wall. Her and her bf have been dating for around a year and they’ve been having sex for a couple of months now. I’m close with my sister so she told me after like the second time they had it. Well they used to always go over to his house but now they only come over here. And for whatever reason, they decide to do it when I’m IN MY ROOM. So of course I can hear them and it’s so annoying because I can literally hear my sister and it’s so frustrating. I personally also think it’s rude that they can’t wait until I’m not in my room? Well anyways this has happened a couple of times now and I’ve had enough so the other day when it was happening I slammed my door and then was really loud. And “dropping things” to get the point across. I also may have hit the wall once or twice. Hahah well they stopped but I’m afraid it’s going to happen again and it’s so annoying what do I do??