in-laws/boundaries

r/

I have a dilemma I’ve been dealing with since me (26F) and my fiance (27M) bought our house in the fall & I need advice to navigate it. We have been together 5 years.

My partners’ parents asked him to move their trailer into our backyard when we first moved in (they bought it with the intention of keeping it at their brothers property) and he agreed to this (we have a large backyard and a small bush/forest at the back of our property). He never asked me if I was ok with this and essentially they are treating it as their “campsite”. He encourages them to decorate as they wish, to stay whenever they want, etc.

His brother, brothers’ girlfriend and their toddler live with his parents and this has caused a lot of issues to the point where his parents don’t want to be at their house ever due to conflict, but they also won’t set their own boundaries. As a result, my fiancé insists they come over whenever they want and even allows them to “hang out” at our house when we are both at work.

With all this in mind, it makes me super uncomfortable and it doesn’t really feel like my home. I’ve spoken to my fiance about this and voiced my concerns and all he did was ask his parents to give a heads up now before they show up. I understand they need a break away from their own house but it feels quite intrusive. I am introverted and I value my space and privacy. His mother is snoopy and every time she is over she takes it upon herself to “clean” our house and always makes sure to point it out which makes me feel bad (even after I have told her to please stop folding our laundry/doing dishes etc). I’m busy with two jobs and things aren’t “messy” but they aren’t always 100% clean. Likewise, she takes it upon herself to decorate where their trailer is and will say things like “oh I’m going to plant flowers all along here and set up string lights”. It upsets me because I had plans on how I want my backyard to look and it doesn’t feel like I’m allowed to do what I want, when I want.

I have a lot of anxiety and I can’t quite explain why the whole thing makes me uncomfortable but I just wish they would get their trailer out of my backyard and take it elsewhere. I’ve been working on communicating this to my fiance but he thinks it’s completely normal and always makes the point of saying “them being in the bush doesn’t affect what you are doing inside the house, it has nothing to do with you and they aren’t bothering you or coming in the house”. But like, then I feel obligated to go say hi? And we don’t have curtains on backside of house so they can see what I’m doing inside if they want…but I don’t want to put curtains up because I enjoy the natural light and seeing outside.

Am I in the wrong here? I feel like it’s weird. But he makes me feel bad for having an issue with it.
For instance, last week I was home alone and his mom texted me at 11pm saying they may stop by the trailer later tonight and were warning me incase I got worried about a car pulling in the driveway. So all night I was stressing out wondering if they were going to show up or not and had no clue if they were spending the night, etc. they ended up coming after midnight and had a bonfire and stayed in the trailer til the next morning. The whole thing is bizarre to me.
Am I being selfish? What should I do?