Mayweather Blames Pacquiao's 'Punk Ass'

Floyd Mayweather is not only blaming Manny Pacquiao for backing out of their big fight -- now the Pretty Boy has resorted to name-calling ... threatening to whip Manny's "punk ass."

I guess he doesn't want the world to know he may have a small pen!s.

Floyd claims he's "thoroughly disgusted" that members of Pacquiao's camp are trying to blame Mayweather for standing in the way of the fight.