Diddy got Diddied lol he got booed on Lopez Tonight!!! hahaha

Diddy made a surprise appearance on "Lopez Tonight" last night -- but the crowd quickly turned on him and actually started booing when he revealed what he was doing there! The rapper showed up to announce he'd be hosting a big party to celebrate his new song "Hello Good Morning" going gold on George Lopez's show next week ... when a different audience would be in attendance.

The crowd wasn't too happy -- but Diddy found a way to make it up to them.

He'll perform with Diddy-Dirty Money on the show next Wednesday, July 28.