This may make you giggle like a group of school girls.
The "Tonight Show" host and longtime master of skits and viral videos had Zac Efron and Seth Rogen dress in drag in a recurring segment titled "Ew!" that aired on Tuesday night's show.
Fallon donned a blond wig and a sundress, reprising a character named Sara ("That's S-A-R-A, with no H, 'cause H's are 'ew!'"), and was joined by the two actors, who wore similar outfits. Franco and Efron are currently promoting their new R-rated comedy film "Neighbors."
In the skit, Rogen, sporting a red-haired wig, joins Fallon in what appears to be a cozy basement, holding a customized Starbucks Frappuccino -- a common order among tweens and teens.
"That sounds amaze-balls -- can I try some?" Fallon asks.
Efron, wearing a straight, dark brunette wig, soon joins them and brags about his new cell phone that has a camera that's "perfect for selfies." He demonstrates by giving his best duck face and snapping one, after which they follow suit. Eventually, Fallon's obviously uncool stepdad, played by "Tonight Show" head writer A.D. Miles, shows up to try to crash the party. Ew!
The three also play a game in which they rank various objects and people, many of which are deemed "ew!"
"OK, last one -- James Franco!" Fallon says, holding up a photo of the actor, who has recently made headlines over a leaked, flirtatious Instagram conversation with a 17-year-old Scottish girl and an almost-nude selfie.
The actor is also good friends with Rogen and starred with him on the 1990s cult series "Freaks and Geeks" and in films such as "Pineapple Express" and "This Is the End."
Watch the entire skit below to see their reaction and find out what "James Franco" did.