"Full House" creator Jeff Franklin says he was double-crossed by one of his co-workers ... leading to Jeff getting fired from the show ... according to a lawsuit.
Franklin says he hired Bryan Behar to be a writer and co-executive producer on "Fuller House" ... but he allegedly spread lies about him to create a "false narrative" that Franklin was a sexist pig around women with whom they both worked.
In the suit, Franklin accuses Behar of taking advantage of the "Me Too" movement and telling Warner Bros. execs that Franklin told female writers to "dress provocatively," commented on their looks and discussed his sex life with them.
One of the most damaging falsehoods -- according to docs obtained by TMZ -- involved a pool party for show writers at Franklin's home. Behar allegedly told execs Franklin demanded female writers all wear bikinis at the event. Franklin insists he merely made suits available for anyone who forgot to bring one.
As for Behar's motive? In the suit, Franklin says Behar was out for his job, and "began plotting a scheme ... by secretly keeping a self-described "little black book'" filled with events he could twist or distort to make Franklin look bad.
Franklin was fired earlier this year, and he points out in the suit ... Behar got promoted to executive producer and showrunner for "Fuller House." Franklin gloats in his lawsuit, highlighting the fact the show's going off the air after its upcoming 5th season.
Franklin is suing Behar for interfering with his ability to negotiate a new contract with WB.