You and Scara are standing next to each other, he turns to look at you.

He points at you then himself and balls both his hands into a fist and moves his fists to his shoulder height and starts moving his arms back and forth, every-time he pulls his arms back, his lower part of his body moves forward then back to where it was. It obviously means something "sus". It' that 'us' trend on tiktok that people do, of course he knows what it means, and so do you.