I've been dating my girlfriend for a few months now. We were both in serous relationships before each other - both of them lasted for about 3 years. She and her ex were big concert people and went to a bunch. Early last year, they bought tickets to a concert late this year that they are both big fans of. They broke up mid last-year.

Yesterday, she says wow I forgot that I have a concert soon that I bought tickets for last year. She said that she bought tickets with her ex to go see the band. She's been a fan of this specific band and said that there's no way that she's missing this concert. I said okay, I'll pay for the ticket your ex had and she said no, he's an even bigger fan of the band than me. There's no way he's missing it. Also, if you want to pay for it he'll probably make you pay resale prices which will be more than 5x the original and that's if he's even gonna sell it which he 99% won't.

I feel weird letting the both of them go enjoy themselves at a concert together. Whenever I say anything about it, she tells me to stop being insecure and just to let her have this moment as she's wanted to see the band live forever. She says that she's gonna be by herself there, she's not even gonna be with her ex because she doesn't wanna see him. I'm not sure what to think about this situation.