Ben Stiller proves he's a kid at heart as he models blonde wig and school uniform for Jimmy Fallon sketch... after discussing being three-years cancer free

He appeared on American television where he discussed being cancer free for three years on Wednesday morning.  

And Ben Stiller, 51, proved he's still a kid at heart when he appeared on The Tonight Show to promote his latest film Brad’s Wish. 

He and host Jimmy wore a blonde wig and a high school uniform for a sketch in which they and actor Fred Armisen pretended to have both starred in a 90’s TV show called Speak for Yourself. 

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STILL down with the kids: Ben Stiller 51, appeared on The Tonight Show to promote his latest film Brad¿s Wish, where he dressed up like a schoolboy and wore a ridiculous wig

STILL down with the kids: Ben Stiller 51, appeared on The Tonight Show to promote his latest film Brad’s Wish, where he dressed up like a schoolboy and wore a ridiculous wig

Recreating an imaginary show that the duo pretended to have starred in together ‘back in the 90’s’, all three of the men donned ridiculous costumes while imitating ‘High school seniors’ at the fictional 'Hinsdale High'.

As part of the routine, both men lip synced each other’s lines, pretending to blame the show’s temperamental Italian director, Giovanni Puccini, who they claimed preferred that the actors swap voices for their scenes.

Ramping up the 90’s styles the actor donned a Letterman jacket and flicked his fake blond fringe sulkily imitating a teenager.

Throwback: Ben emphasised all of the over-exaggerated performances of the 90s as he delivers his fake-catchphrase, yelling: 'Say what?!'

Throwback: Ben emphasised all of the over-exaggerated performances of the 90s as he delivers his fake-catchphrase, yelling: 'Say what?!'

In three scenes Stiller's character, who's called Reggie, fights with Fallon's over the affections of their mutual love interest, Jessica Pinkus.

Still dubbing each other's lines they both pretended to perform childish love poetry or songs they'd written.

Former Saturday Night Live comedian, Fred, dragged up with a long blonde wig to join them as the high school girl who the men were warring over.

Wigging it: The Tonight Show often does sketch routines thanks to host Jimmy Fallon (right) who used to be a cast member on the improv institution Saturday Night Live

Wigging it: The Tonight Show often does sketch routines thanks to host Jimmy Fallon (right) who used to be a cast member on the improv institution Saturday Night Live

Loud and proud: Ben is well known for his comic timing and playful sense of humour 

Loud and proud: Ben is well known for his comic timing and playful sense of humour 

Ben's status: Stiller 

Ben's status: Stiller revealed he has been free from prostate for three years when he appeared on The Today Show to talk up his new movie, Brad's Status, in New York on Wednesday

Ben also appeared on the Today Show where he said: 'I'm three years now cancer-free and I'm really happy!'

While publicising his film the 51-year-old was urging men to check for prostate cancer after he himself was diagnosed.

The comedian talked with host Matt Lauer about the importance of being tested, drawing attention to the PSA, a simple blood test that gives early warning of prostate cancer. 

King of drag: Actor Fred Armisen is well-known for his performances on his cult TV show, Portlandia

King of drag: Actor Fred Armisen is well-known for his performances on his cult TV show, Portlandia

The Zoolander star’s latest film was written and directed by Mike White and shows the journey of a father who takes his son on a tour of East Coast colleges, who begins to feel inferior about his life after watching his old friends on social media.

A late-life coming-of-age story, his character begins to suffer a midlife crisis just as he should be helping his son get into Harvard.

It hit the American Box Office on the 15th September and stars a host of comedy legends including the Welsh character actor Michael Sheen and Luke Wilson, the brother of Own Wilson, who has also appeared in numerous films alongside Stiller.

Late-life coming-of-age story: According to the film's tagline - 'The success you've been searching for may be right next to you.'

Late-life coming-of-age story: According to the film's tagline - 'The success you've been searching for may be right next to you.'

Brad's Status: In the film, which was released on 15th September in the US, also stars the young-actor Austin Abrams who plays Brad's son.

Brad's Status: In the film, which was released on 15th September in the US, also stars the young-actor Austin Abrams who plays Brad's son.