Last July during the New York stop on the Floyd Mayweather vs. Conor McGregor world tour, the UFC lightweight champion dragged 50 Cent into his trash talk, and an unlikely beef was born . Mayweather and McGregor fought the next month, of course, with McGregor losing by 10th-round TKO , so no need for the McGregor-50 Cent beef to ever flare up again. Right? WRONG. Fast forward to earlier this week, and McGregor found a way to mention 50 Cent in a lengthy Instagram post celebrating his new endorsement deal with Burger King