London, Feb 23 - Porn star Bridget The Midget surprised Rihanna by treating the singer with a raunchy lap dance on her birthday.

The 'Umbrella' hitmaker celebrated her 22nd birthday in Phoenix, Arizona Saturday. It was a surprise party thrown for her by rumoured new boyfriend Matt Kemp, reports contactmusic.com.

Rihanna, who later moved to a local bar with her friends, was singled out before the adult star began dancing around her chair.

IANS