My girlfriend and brother slept in the same bed (no sex) Should I be mad?

1. They were both and their group on schoolies trip, a big celebration school leavers have at the end of the year. I'm 2 years older than her

2. There were other guys and girls in the room

3. She says she couldn't get back to her apartment...even though they were on a top floor and hers was a bottom floor.

4. They both didn't tell me at all, I was just generally asking about the trip to my brother and it came up, she didn't mention about it at all..

5. She says she's liked me all along, but just before she got with me, I know she was with another guy that she did stuff with..

Updates
+1 y
My brother says I have reacted all wrong about this, I kicked him out of my place. Am I overreacting?
Updates
+1 y
Still just so confused with everything? How would you try and deal with this?
My girlfriend and brother slept in the same bed (no sex) Should I be mad?
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