<human>: Summarize the given text in a few sentences.

We were together for two years and broke up four months ago. Two weeks after we broke up he started dating this girl and it was a massive blow. I was really worried about them dating and I felt uncomfortable about her for a while before we broke up. When it happened I had a panic attack and she was a mutual friend. 

He and I were each other's first everything and he was incredibly possessive and terrified I would leave him for someone else. The irony of the situation isn't lost on me.

He is in my group of friends and we've both done our best to make sure no one has taken sides but he really wants her to come to social events. He asked me if I would be ok if she came to a party of a mutual friend and I said no I wouldn't be. He's respecting my decision for the moment but he keeps reminding me that eventually she has to hang out with our friends.

 Am I being unreasonable by not wanting to be around her or saying that I don't want her around? It still hurts a lot but he keeps saying that he gets lonely at parties without her. I feel slightly ridiculous but I get really anxious at the thought of being around her. He keeps saying that she doesn't have to attend everything but I know that once she comes to one party she will be integrated into hanging out with us on a regular basis.
<bot>: Ex-bf keeps asking if his current gf can attend parties as he is lonely without her. I say no because it makes me really anxious. Am I being unreasonable?