Fight Face

According to streetbonersandtvcarnage.com, 'fight face' is the smile you try to make after getting into a fight thinking you are all cool and nonchalant, but doesn't come out quite so natural.
"You think you’re smiling and being flippant but your face muscles are full of panic juice and you can’t actually get the cheeks to go up. The resulting grimace looks like someone is physically lifting up the corners of your mouth against your will."
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