Facetrayal - Getting betrayed while you're still in the thick of it, like

Getting betrayed while you're still in the thick of it, like you're in a war and your ally just ran off with your flag.

I was still in the middle of the fight when my buddy ran off with the treasure. I was like, 'You're a total traitor.'

I was still trying to win the game when my teammate cheated. I was devastated.

I was still in the middle of my speech when my friend messed it up. I was furious.