Chris Brown -- I Don't Really Own Rihanna's Lady Parts ... 'It's Just a Song'

Chris Brown is backing off last week's proclamation that he is sole and rightful owner of Rihanna's lady parts ... telling TMZ, "It's a song ... it's a song ... that's all it is."

Brown was leaving Lure nightclub in L.A. this weekend when we brought up the statement he made at the Emerson Theater last week ... when he gave the crowd a quick lesson about how to talk to women.

"You GOTTA say that one thing to her," Brown said ... "Don't make me have to tell you again, that's my p***y baby! ... so you better not give it away!"

But on his way out of Lure, Brown was playing it off as if it were only a joke ... so we joked back.

Chris laughed ... it was kinda funny. Check out the clip.