<human>: My girlfriend is going to a concert with her sister and an ex boyfriend of hers. They'll more than likely be staying the night and driving back in the morning. She insists her and her ex boyfriend will be in separate rooms.

When she first suggested the idea I told her that I was 100% against it and I didn't want her going with him. She bought the tickets with him regardless so now it's all sorted.

I see this as totally unacceptable and if the situations were reversed there is no way she would be okay with me doing that. Am I just being overly dramatic or would this be cause for concern for anyone else?

Can you give me the gist of the text in a nutshell?
<bot>: Girlfriend is travelling miles and possibly staying in a hotel with an ex boyfriend, am I over reacting or is this a big deal?