Robin Thicke - making headlines.

FH has learned that the NYPD busted the sexy R&B crooner - for get this - riding dirty!

Yes Paula Patton's hubby - was arrested for drug possession!  Cops say the singer was smoking weed, reefer, marijuana, or whatever you call it, while inside a black Escalade.  But get this, cops were so star struck, they asked Thicke for his autograph, and he even posed in pictures with some of the officers.

In the end, Thicke was given a desk appearance, ticket and was released.  

FORECAST: Robin, I'm sending some clouds your way.  If you're going to smoke a doobie make sure you do it in the privacy of your own home or wherever, but never, never, in a public place where people like the police can catch you, boo!  Oh, cause of course people like ME will write about you and point out how irresponsible you were! SMH.