Floyd Mayweather is mocking Manny Pacquiao -- and he wants the world to see it -- more proof he's trying to bait the fighter into a rematch in 2020.
The undefeated 42-year-old was signing autographs at the Art of Music shop inside the MGM Grand in Vegas over the weekend ... when a fan asked Floyd to sign a ticket from the 2015 Mayweather vs. Pacquiao fight.
Get this ... fans were NOT allowed to carry cell phones while interacting with Floyd, but when Mayweather saw the item, he told the fan to go out and grab his phone so he could record "something special.