Time ostenibly spent in the bathroom (derivative of "to flex" = Pooping) but more to the point spent at other pursuits - video solitare, reading the newspaper, collecting your thoughts, jerking off, or all of the above - while in the stall and/or bathroom. Occurs daily worldwide.
Dave stood, grabbed the crossword puzzle and headed for the bathroom. "I'm going to take some flex time," he announced
A benefit that an organization may offer its employee's that allows them to choose work hours that harmonize with life activities outside of work.
Hey Honey, with the flextime this new job offers, we can make love before we pick up the kids from school!