AITA for sending away the pet chicken that my girlfriend and her daughter bought without my knowledge

I've been dating my girlfriend Amy for over a year and a half at this point. Her daughter Kelly is 8 years old. Amy and I aren't living together yet, we have been discussing the idea for a few months now however. Amy had mentioned that prior to her and her daughter moving in with me, she would need some assurances. For example, that I would get a better job (I work in a warehouse doing maintenance) and that I cut back on drinking and smoking. I also need to fix up my house a bit because Amy and Kelly are very neat, where as I'm just a average guy who keeps up with the bare basics. <br><br>Amy and I were talking on the phone one night when she brought up chickens. For context, my house is in a rural area and on a 1 acre lot. I have a fence around a good portion of my property. Amy and Kelly went to visit a friend over the weekend and apparently, this friend had chickens. Amy told me that Kelly really enjoyed feeding them and how happy it made her to see her daughter so excited. <br><br>At the time of the call, my house was a mess because I had just moved some walls in my house and I was still in the process of putting down new flooring. I told Amy that maybe we could consider it in the future but, at the time, my house was a mess and I didn't think it would be a good idea. Amy said OK and we went on with the conversation like normal. It wasn't until a few days later when I came home from work that I found out that they went ahead and purchased the chicken. <br><br>I'm not happy about being undermined but, I figured I would just deal with it considering it was only one chicken and they were taking care of it. They kept it in our garage for the first week with plans on building it a home outside in the spring. That's when the problems started happening. For example, when Kelly was at school she would forget about feeding or changing the food and water for the chicken. Amy gets home around 4:30PM but, Kelly is usually picked up after 5PM from after school program. I would come home from work and the chicken would have no food or water. <br><br>Sometimes I would come home from work and find the chicken was outside of it's cage because the chicken had gotten out. The garage I have is 2 cars with a additional 2 bays for extra room. It was in one of the larger bays. They had chicken wire blocking it in but, the chicken was smart and would squeeze it's way out. I would have to wrangle the chicken outside in the snow and get it to go back into it's little house. <br><br>I went out of town for 3 days for work and I returned home to find the chicken had escaped and had shit all over the floor of my garage. It was a mess and it smelled terrible. That was the final straw, I said that we would either be taking the chicken back where we got it or giving it to a farm. Amy yelled at me and said it's not the chickens fault and I should take responsibility for taking care of it. I told her I'm not taking care of the chicken anymore and she can either take it with her or it's going. <br><br>Amy got very angry and said that I'm being immature and petty. I had a man from Craigslist come and pick up the chicken the next Saturday. Amy has not spoken to me since and we've been arguing about it via text message. Amy is saying that I'm being mean and I'm not considering my step daughter. I feel like I have compromised. I told Amy that I would reconsider getting the chicken back if Amy and Kelly would clean my garage. They both said no and that I should do it because it's my fault the chicken shit on the floor.