A fork of Rural Dictionary
(Abbreviated to FMPD) Someone who portrays themselves on Facebook completely differently to how they actually are/behave in real life.
i.e A quiet introvert in real life, but who frequently comments, makes jokes/banter over Facebook. Polar opposite personalities
"That Tommy has got serious Facebook Multiple Personality Disorder! Quiet as a mouse in real life... yet on FB he's the life and soul of the party..."