50 Cent Folds Like Cheap Suit After Fat Shaming

50 Cent crossed the line, and he knows it ... retreating big time after taking a shot at Diddy and his competing vodka ... at the expense of an overweight woman.

50 is now endorsing EFFEN Vodka and decided the best way to promote his brand was to go after the competition ... Diddy and Ciroc. But the way he did it was super offensive, posting a photo of Diddy grinding up against a large woman ... equating Ciroc with banging large chicks.

It didn't take long for people to go on the attack, and 50 just waived the white flag by pulling down the post and pretending it never happened.

So much for his EFFEN cheap shot.