Anti-flex

It is when you underestimate something you did, which is really challenging to others as if it was nothing so that you sound like you are modest and don't want to flex, but in reality, you are just flexing implicitly.

-So I forgot the formula during that test, but I derived it quickly by neglecting the value of "such and such" and canceling "term" with "term" to derive the formula in a not-very neat fashion XD, gosh I'm so stupid!
-Bro, stop anti-flexing.

-I was getting bored lately with the Java syntax so I made my own programming language, it is a stupid language tbh.
-ngl that was a good anti-flex.