<human>: Can you succinctly summarize the text in 1-3 sentences?

Throw away for obvious reasons,
Next Saturday my girlfriend will be going to a party that a friend invited her to, they will be hanging out all day, and going to dinner at night. She also told me that her Ex was coming to the party as well. I wasn't sure whats the proper way to react or feel about this? How would you guys feel?

I feel a little jealous for starters, almost betrayed. I'm extremely protective of my girlfriend, so to hear that she's going kind of hurts. Mostly because she has such a hard time finding time for me anymore, so I'm a little concerned.
Should I be worried? Would you guys let your girlfriend go to a party without you, knowing their ex was there?
<bot>: Girlfriend going to party without me, ex will be there, I'm jealous and uncomfortable, how should I react?