Katy Perry

Katy Perry premiered the music video of her nerdy alter ego Kathy Beth 'Last Friday Night (T.G.I.F.)'.

Originally planning to spend the night on her bed, Kathy is corrupted by Rebecca Black when coming over to her home to confront her regarding some noise. The geeky girl is persuaded by the YouTube sensation to enjoy the home party instead.

The morning after, Kathy wakes up in her own bed next to a shirtless guy but doesn't remember a thing about last night. "There's a stranger in my bed/ There's a pounding my head/ Glitter all over the room/ Pink flamingos in the pool/ I smell like a minibar/ DJ's passed out in the yard/ Barbie's on the barbeque/ There's a hickie or a bruise/ Pictures of last night ended up online, I'm screwed," she sings.

Kevin McHale(Glee) portrays a nerdy boy who becomes Kathy's knight in shining armor. Darren Criss (another Glee star) also makes a cameo as another boy who is left impressed by her after the wild gathering. Kenny G and Hanson help keep the crowd going with their music. Corey Feldman and Debbie Gibson are the cool mum and dad.

Watch the music video below: