AITA for exposing the guy my girlfriend let replace me and take credit for my idea?

At dinner, my girlfriend laughed and said she wanted someone “actually impressive,” then let Cole smirk like he had already replaced me. I paid my half, left without a scene, and a week later watched him explain to a review panel why his big idea had my name, timestamps, and an email trail all over it. ---------------🐋Whale Tales🐋--------------- #reddit #stories #redditstories