kimbeerbong.jpgphotos courtesy of E!

Kim Kardashian is 30 years old, and who says you can't celebrate your birthday being held upside down, by your thighs, doing a keg stand?

While partying in Las Vegas, Ms. Kardashian and some gal pals got the party started in their swanky hotel room. No worries, mom Kris Jenner was right there to make sure everything went smoothly.

This foamy footage will be part of an upcoming episode of E!'s Kourtney and Kim Take New York.

Big bottoms up, Kim!