Justin Bieber's Party Pals

Kim Kardashian! Katy Perry! See the stars sure to wish the singer a very happy birthday when he turns 17 on March 1!

RIHANNA

"It's always love," Tweeted Bieber while grabbing dinner with Rihanna. The teen pop star apparently gave Rihanna more than she bargained for: "Justin Bieber just flashed me his abs in the middle of a restaurant! Wow! He actually had a lil 6-pack! Sexy, lol!" Rihanna Tweeted.