So I am a 20 year old woman living in a large house by myself. I have a massive garden and have always loved cows from a young age so when I was 18 I bought 4 calves. There names are Freddie, Tommy, Bobby and Leo. 3 days ago my mother (a 57 year old woman) asked to come stay at my house temporarily because hers is having major work done. I agreed and began organising the house for her. (She is aware that I own cows) When she arrived I was very surprised to see she had a dog with her. She had not told me she owned a dog let alone that she would be bringing one into my house. I confronted her and she said it was trained so it would be fine. I was still unhappy that she hadn't let me know but I went along with it. Suddenly her dog ran into the garden were my cows are. My cows got very stressed and started running around and mooing. My mother was apologetic and took her dog inside. It was getting late so I put the cows in their shed. Then in the early hours of the morning I heard barking and mooing coming from outside. I went downstairs to see what it was. My mother had purposely let her dog out into the garden again and it was scaring the cows. I confronted my mother and she said 'it's fine they're just getting to know each other' I was angry but I stayed calm and brought the dog back inside. I told her I don't want this to happen again. The next night the same thing happened. She claimed it was an accident. At this point I was very angry. My cows were very scared and the dog was scratching at their shed door. I snapped at my mother telling her that if her dog can't behave then I won't have her or it in my home and around my animals. She replied with: I am your mother I basically own your house because I raised you. Now this is where I got my revenge. My mother went out for the day with her dog, leaving her belongings messily scattered around the room. (She was sleeping in the living room so her mess meant I couldn't sit down there)Here's where I may be the asshole: I went outside and opened the shed door for my cows as usual. However I also left the back door open that had let her dog out into my garden from the living room. Then I went upstairs and waited. About 5 minutes later I could hear the cows downstairs in her room and could see them stepping through the open door. 1 hour later my mother came back and screamed. I ran downstairs to see her standing at the door to her room staring at the cows. All of her belongings had been bitten, spat on and stepped on. Freddie suddenly pooed on her £90 dress and Bobby was rubbing his head against her lamp. She got very angry and shouted at me. I said it was 'an accident' like when her dog was 'accidentally' let out. She called me an asshole and other rude things and told me I had to pay for the damage. I refused and started stroking my cows. She left the house with her dog. I posted her the belongings (I did not clean them or pay for the damage) she is now staying at my brothers home. So Reddit am I the asshole for letting my cows trash my mothers things?