Rihanna celebrated her birthday on Saturday night with boyfriend Matt Kemp, a few close friends … and a little person who gives lap dances.

Rihanna

It all went down in Arizona … during a weekend in which RiRi went barhopping in Scottsdale.

What more could a girl want?

UPDATE: The tiny dancer is “Bridget the Midget,” a porn star who also appeared on “Cathouse.”

See the video: www.tmz.com/videos?autoplay=true&mediaKey=a19e1682-90e8-4db6-ab88-132c44283f37