Why do I keep being invited to my ex's party ?

My ex and I have been broken up for 7 months already. 2 months ago, she invited me to her birthday party and I declined the invitation. She asked again, insisted even, I declined again and she called me an ahole. <br>Now I got a message from her saying I'm invited to her Christmas party, and I'm sitting here wondering. Am I just being petty when I'm still hurt by her insistence on inviting me to her party? <br><br>For context, we've been together for almost 2 years and we parted ways due to cheating. <br><br>PS: I blocked her number already and only talking to her through messenger.