Katy Perry Gets Slimed, Kisses Justin Bieber

Credit: Kevin Winter/Getty Images for KCA; Twitter

Katy Perry had an action-packed night at Saturday's Nickelodeon Kids' Choice Awards.

The singer, 25, laid a smooch on Justin Bieber, 16.

"Told you I would tap that. Yummy," she joked on Twitter.

PHOTOS: Katy -- and other stars -- partying at the Oscars

The bright-blue wigged Perry got doused in green slime when she announced Miley Cyrus as the winner of the favorite movie actress award, which she presented with comic Johah Hill. (She cleans up nicely, though. Perry was spotted at blogger Perez Hilton's 32nd "Carn-Evil" birthday party later that night.)

PHOTOS: Katy's scandalous dress choice

"Thank God we both wear wigs," Cyrus -- who won for Hannah Montana: The Movie -- joked while accepting the network's signature orange blimp trophy. "Thank you, Katy, for not sliming me."

New couple Joe Jonas, 20, and Demi Lovato, 17, hit the event together.

"He's a great guy and you can't always genuinely say that about guys in the limelight," Lovato told UsMagazine.com on the red carpet. "I can really count on him. He's a great friend and has always been there for me. And he and his brothers make great music! What's not to like?"

PHOTOS: Hollywood's power couples

Big winners of the night: Taylor Lautner and Kristen Stewart, who took home the cutest couple award for New Moon.

"I have to admit, I have always dreamt of winning one of these orange blimps," said Lautner, who also took home the favorite actor award. "Seriously."