AITA for abandoning my girlfriend's kids and not checking on them?

My girlfriend, Jess, has two kids, a boy (7) and a girl (4). Their dad died a year ago and I've been dating Jess for three months. I've only gotten to spend time with the kids a few times, as I've been out of town for work.<br><br>Kids hate me. They see me as a replacement for their dad and they don't want me around. They go from ignored to being the center of attention, depending on Jess's mood.<br><br>Jess is very defensive of her kids. To the point that I've broken up with her multiple times before getting back together.<br><br>Jess's friend was getting married and she invited us. I was told it was an adult-only event. Jess insisted on bringing the kids and Jess's mom said she'd babysit. The kids were upset and I suggested finding another babysitter. Jess said she could handle it and that the kids would behave.<br><br>The morning of the wedding, Jess was a mess. The kids kept pulling on her dress, wanting to play. We were already running late and Jess snapped, saying she couldn't leave the kids alone for a few hours.<br><br>I finally said I couldn't handle it anymore. I'm not the kid's dad and I'm not responsible for them. I told Jess to find another date for the wedding.<br><br>Jess was furious. I just walked away. I had enough and didn't want to be a part of this anymore. I went to the wedding alone and had a great time.<br><br>Jess called me later, screaming at me. I told her I'm done and that I couldn't keep being put in these impossible situations. We broke up.<br><br>I've been told by everyone that I was a massive asshole and I'm getting shit for not checking on her kids. I'm not the kid's dad. I don't owe them anything. AITA for this?