Sumo flex

To brag or boast about your personal belongings or accomplishments

Man Keaf just got a new Rolex he was on Snapchat sumo flexin

by BlatlanticK ReKords May 5, 2018

Flex Tape

The true name of Hanta Sero’s quirk.

Person 1: That’s Cellophane! He’s the Tape Hero! His quirk is Flex Tape!
Person 2: wow, fanboy much? And I thought it was just “tape.”
Person 1: no it’s Flex Tape

by DraconicOxalis April 13, 2021

flex the rainbow

When the penis shaft bends slightly during homosexual anal intercourse

when you flex the rainbow in Shane he really likes it!

by Literalistic September 30, 2023

Dick flex

When you flex your dick inside your partners throat

Last night I was getting head and I flexed my dick in her throat she was so mad it made her gag- dick flex

by Harryharold August 30, 2019

Flex seal your god damn mouth

Another way to tell someone to shut the fuck up because they won't stop being a fucking fortnite player

Kenny I with fucking flex seal your god damn mouth shut you gay fortnite player.

by I love izzie999 April 15, 2021

Flex

the word flex usually means to bend a joint, but in this case, to flex something means to steal something that is not yours, so its a verb.
my friend created this word so i added it because i thought it would catch on.
flex, present tense
flexed. past tense

"Alex, that dude just flexed your phone"

by diamondman200 May 6, 2018

Flex

Man who has been through a lot, but has managed to stay strong through it all. (Flex)

Aye, dat nigga Flex gotta strong cock, man.

by Dat fat dick ass nigga July 16, 2017