<human>: Can you condense the text into a few key points?

I was walking to my girlfriends class to pick her up and as I got about 100 feet away my ex walked up to me and tried to hug me. I declined, not knowing my girlfriend was watching and gave her a high five instead. We're still good friends mind you me and my ex. But my current girlfriend hates her for several reason such as my ex trying to win me back and other trivial bull shit. My girlfriend wouldn't even let me walk her to her class after. She even threw away the lunch I ordered for us. She still talks to her exes and I don't really complain, no matter how much I hate some of them. I just don't see how she could get so mad over a high five.
<bot>: girlfriend of over a year saw me high five my ex. Got visible angry and nearly threw a fit in public. She also threw away our lunch. Is this even remotely justified?