The Sigma face is a face where while smiling you suck in your cheeks (Hey! Not those ones). You can nod your head and make some other faces while sucking in your cheeks. Some people call it the sigma face or TopG face.
In the movie 'American Psycho' you can see Patrick Bateman kinda doing it.

You can also do it after doing something cool

Step by Step Tutorial:

1. Suck in your cheeks

2. Slightly bite the inside of you cheeks
3. Smile

4. Raise your eyebrows

(Never stop sucking he he)
5. Now you've done the GigaChad face, good job!
by Duckcid May 2, 2023
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