What I think is happening is locker room humor .... calling Army assholes.
It’s the circle game. Making that gesture with the hand below the waist means that if someone notices it, you have the right to punch them in the shoulder. A little immature perhaps, but not “white power.”
“What I think is happening is locker room humor”
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It’s “Circle Game” kid horseplay.
https://en.wikipedia.org/wiki/List_of_school_pranks#Circle_game
Used to do something somewhat related when I was a kid - asked a guy if he ever tried a “Hertz Doughnut”. When he says “no”, you punch him in the shoulder and say “Hertz, doughnut?” (”Hurts, don’t it?”).