Is NOBODY wrong in the post ? POST : My gf (28) was previously married, she got a notice late last year that her divorce will be official as of the 2nd of February. When she told me I told her I'd love to celebrate it with her that day. She said she'd love to and we left it at that. 

A few days after that I over heard her on the phone with her friend telling her about the divorce and that they should get together and celebrate it on the 2nd of February. Wait, what? I thought that's what we were gonna do and so I asked her about it. She told me that she didn't mean it that it was just girl talk and that we are celebrating it. 

Fast forward to this week. She tells me that her friends want to get together Friday night around 10pm to go cosmic bowling and have a few drinks. I immediately asked her if this is them celebrating her divorce and she said no. Said she didn't plan this and that it's just coincidence but if they can kill two stones with one bird why not?  

Because of my new job I have to work nights and weekends so I can't celebrate it with her. I wasn't upset that she was gonna celebrate it with her friends but I feel like she lied to me when I first asked and that she's lying now. 

I got upset and told her I was upset and that I prefer she cancels on them Friday (this part I know I'm being petty about) but am I the asshole for feeling this was and basically starting an argument today? 