Will.i.am, Jimmy Fallon Become Teenage Girls for Hilarious "Ew!" Music Video: Watch!

In the words of Will.i.am's teen girl alter ego Mir.i.am, "OM effin G!"

The "Feelin' Myself" singer teamed up with Jimmy Fallon for a totally amazing "Ew!" segment on The Tonight Show on Monday, October 6, starring in a music video as a headgear-wearing teenager alongside Fallon's recurring character Sara (no H).

The duo's song (appropriately titled "Ew!") is a musical montage of all the things the two young girls find unappealing in their teenage lives — from duck lips, to impleggies (butt implants if you didn't know!) and FaceTime.

"I'm freaking Pharrell, I think silicone butts are ew!" raps Mir.i.am.

Fallon then embarks on a crazy fast-paced rapped list of all the things Sara finds "ew!" before ending on a piece of teenage wisdom: "Haters gonna hate!"

Will.i.am joins an impressive list of Fallon’s former “Ew!” costars, including Michelle Obama, Lindsay Lohan, Taylor Swift and Zac Efron.

Check out the whole video above. Warning: you may have this tune in your head for the rest of the day!

The song is available for digital download on iTunes, to raise money for the SeriousFun Children's Network and the i.am.angel Foundation.