Warren Sapp To Jeff Garlin -- I Never Bullied You ... 'Stop The Lying'

Move over Tupac and Biggie ... sit down Tara Reid and Paris Hilton ... a new celebrity beef has kicked off between "Curb Your Enthusiasm" star Jeff Garlin and NFL Hall-of-Famer Warren Sapp and it's well, really, really, weird.

Garlin, who currently stars in "The Goldbergs" on ABC, appeared on "Sway In The Morning" and trashed Sapp saying Warren PHYSICALLY THREATENED and "bullied" him when they met in an airport some time ago.

Here's the twist ... Sapp was the next scheduled guest on Sway's radio show -- and when Sway asked him about the beef, Warren told a COMPLETELY DIFFERENT version of the airport story!

Warren told Sway he also remembers the encounter ... but he makes Garlin out to be an obsessed fanboy and called upon Jeff to "stop the lying."

So, who's telling the truth??? Check out the clip ... then pick a side!!