Mike Epps -- Apologizes for Racist Pic ... It Was Just a Joke From My Nephews

Mike Epps just thought it would be funny when he posted a photo of a black man whipping white men slaves -- and says the whole mess started as a joke with his nephews.

Mike came on TMZ Live to discuss the controversy over the image, telling us ... he thought the photo was absurd and funny -- but he understands why some people were angry. Ultimately, he says that's why he deleted it.

Mike has a new AOL series -- "That's Racist" -- debuting on Monday ... where he'll be interviewing people around the country about stereotypes, but insists the pic was NOT intended to be a promotion.

As for where the controversial pic even came from -- you gotta hear his explanation. Sorry kids ... Uncle Mike just backed up the bus.