Feb. 21, 2014 at 1:26 AM ET
This has been a week of "firsts" for "The Tonight Show Starring Jimmy Fallon" — including a visit from the first lady of the United States. But Michelle Obama did more than a traditional interview: She joined comedian Will Ferrell and Fallon for "Ew!" — one of the most popular sketches from Fallon's "Late Night."
This isn't FLOTUS' first Fallon rodeo. She most memorably showed off her moves in "The Evolution of Mom Dancing," a version of the routine Will Smith performed on Monday's first "Tonight Show."
In "Ew!" Fallon channels teenage Sara, the "ew"-opining, braces-sporting host of a TeenNick show filmed in her basement of a house. In the latest skit, Sara's guests were "Stacy Wallace" — Ferrell in pigtails and a halter minidress — and Mrs. Obama.
The VIP was game for everything — aside from making out, like Ferrell did with a Harry Styles poster. That included a "shy faceoff," a "triple hand hug" with the "girls" and a dance party (before they were interrupted by Sara's dorky stepdad, Gary).
The first lady was diplomatic, but she did offer a few disdainful "ews" of her own: to jelly doughnuts (the Let's Move initiative founder offered her co-hosts kale chips instead) and the movie star Will Ferrell (Stacy disagreed and made out with a Ferrell headshot).
Mrs. Obama is dealing with two teenage girls of her own, but "Sasha and Malia don't say 'ew,'" she confirmed during her interview with Fallon after the skit. But she has bigger things to worry about: Malia will be getting her drivers license when she turns 16 this summer.
"Ladies and gentlemen of D.C., watch out," she warned with a laugh.
But it's 20-somethings whom we should really worry about, Mrs. Obama suggested, and pleaded with parents to encourage their adult children to sign up for health insurance via the Affordable Care Act.
"The truth is, young people are knuckleheads," she cracked. " They're the ones who are cooking for the first time, slicing their finger open."
After swapping stories about their first school dances, Mrs. Obama ribbed the host for being "one of the sweaty ones." He tried to prove otherwise by shaking her hand — but even though he wiped it down, she pretended to recoil.
"Ew!" she exclaimed.
And that's how you drop the mic on "The Tonight Show."