An Art! it is the art of managing to flirt while texting.
Girl: hey alex, what are you doing? put your phone away
Alex: I can't. this is reall important
Girl: are you flirting with another girl?
Alex: nope, just flexing
A cross between a popular brand of toothpaste and the ever-ready sales assistant of WH Smith in Derby.
Flex, do you have the new issue of Tractor & Heritage Magazine?
The process of running away from trouble/harm.
Dude, the cops are coming around the corner. Flex it!!
Jack: I go to bed at 8
Jill:I go to bed at nine suck my penis
Jack: Jill you do not have a penis
Jill: nobody gives a fuck and stop flexing your penis
"Last night I flexed this absolute babe",or "She was definately down for the flex"