AITA for waking up my house and ruining thanksgiving for everyone

My grandmother died last year and the main thing we inherited was a house with a lot of land and a lake connected to it. Our family put the house up for sale and the realtor had a company that could stage the house, giving us a more modern look and making it look bigger, I guess. The people who are currently in the house have been there since last month and they have to leave by the end of December. We actually get 3 days a month to spend in the house and use it as we please. For my birthday, my fiancée and I chose to go there with my sister and spend a nice weekend out of city. <br><br>We set up the reservations for mid November, so imagine our surprise when my parents announced they wanted to have thanksgiving at the lake house. I checked with the realtor and sure enough, the family had left a couple of days before, giving us two more days until the next family arrived. This meant that yes, we could go, and we did. We thought it would be nice to get there a day earlier than my parents, my sister and her husband, and my brother and his fiancée, to put the food together and everything. <br><br>We arrived, started to put the stuff away and found a note on the counter. “Please don’t touch anything or you’ll be charged” (or something like that). So, I called the realtor. I was told that the people had left and that we could stay in one of the rooms, just please don’t touch anything and don’t get anything that wasn’t ours. We agreed and went to sleep, ready to start cooking the next day. <br><br>The next day, we woke up at 6 and started cooking. We were in the middle of it when my family arrived. They saw how quickly we were able to get the food ready and asked how we did it. My fiancée answered by telling them what they had said and I told them that they could sleep in their rooms if they wanted to. <br><br>Chaos erupted. I got called things I won’t repeat, my parents told me that I ruined the celebration, family left and the people who were going to buy the house backed out. They said that they had received a call from a relative of mine saying that two strangers had been in the house. They didn’t want the house anymore fearing that two strangers had been there for months and had taken advantage of it. <br><br>My parents said that they payed for the house and they should have the last word in it and that I ruined their thanksgiving. My fiancée told my parents to grow up and that if they wanted a celebration they should have arrived the day before. My dad told her that she was part of the problem and that soon she wouldn’t be part of the family anymore because I would get rid of her. <br><br>I can’t see how I’m the AH here, but I guess I can be a little biased. I want to know if I made a mistake.