Refers to something that an individual would deem widely accepted or cool to show off, but in reality it just makes them look like a fucking idiot/weird.
Example 1:

Person 1: Strawberries on Pizza are to die for.
Person 2: This ain’t it Chief.

Example 2:

Person 1: Who’s excited for the new Teen Titans GO Movie??
Person 2: This ain’t it Chief.
A term said when a situation is not going to your liking
Jeff: Bertha friend zoned me
Kazoo: This ain’t it chief
by Snoop dog$$$$$ January 20, 2019