Much like Peep Show, it's understandable that some people assume that the stars of gross-out-but-sometimes-oddly-sweet teen sitcom The Inbetweeners - Simon Bird, Joe Thomas, James Buckley and Blake Harrison - actually wrote the show, as they seem to fit their characters so well. Not so, however - that honour belongs to (Damon Beesley and Iain Morris) but Bird and Thomas are in fact pretty experienced comedy writers, having performed (and impressed) at the Edinburgh Fringe with their show The Meeting, created with award-winning stand-up comic Jonny Sweet.

For Chickens, these three have got back together and produced a properly entertaining half hour pilot in which they play the only three men left in a pretty Heart-of-England village during the First World War. They each have their reasons for staying behind: Cecil (Bird) isn't allowed in the army on account of his flat feet, teacher George (Thomas) is a conscientious objector and Bert (Sweet)... well he just finds it difficult to remember there's a war on, what with all the girls (and women, and old ladies) of the village distracting him the whole time.

There was an element of farce about this - Cecil ends up accidentally peeing on a tree planted in remembrance of a dead soldier - but as with so many sitcoms, Chickens actually works best when it's just the three leads chatting and bickering. Jonny Sweet, I think, pretty much steals the show. As a self-centred lothario, he's simultaneously incredibly creepy and massively watchable - here, as with his stand-up, it's his delivery that makes him so much fun. All the best comics can make an apparently simple word sound hilarious and Sweet is no different. Just take a listen to how he says the word 'crow'.

'The Inbetweeners Movie' premiere - in pictures

The Inbetweeners Movie held its world premiere in London yesterday, with stars Simon Bird, James Buckley, Blake Harrison and Joe Thomas turning out to launch the film to UK audiences.

Video: The Inbetweeners on the big screen

Actors Simon Bird, Blake Harrison, Joe Thomas and James Buckley star as four teenage friends in the TV comedy The Inbetweeners.

They are now making their debut on the big screen with their film called The Inbetweeners Movie.

The film premieres in London on Tuesday evening. The cast spoke to BBC Breakfast about what fans can expect from the film.

It's the Grimbetweeners

Cheer up, lads - your luck with the girls could finally be in. Actors Blake Harrison, James Buckley and Joe Thomas all look a bit glum as they start filming The Inbetweeners movie.

A tanning disaster as Inbetweeners movie starts filming

As Neil Sutherland in The Inbetweeners, Blake Harrison's character is known for being a bit slower than his friends. But it appears the teenager isn't well educated on the dangers of tanning either as Harrison was spotted with a sunburned face on the set of the upcoming movie spin-off.

Joe's the one with balls

Blake Harrison, who is dippy Neil, said: "We've worked out now that if we all look unenthusiastic, they'll get Joe Thomas (aka Simon) to do it. He'll do pretty much anything, he has no shame."

I had hopes for The Increasingly Poor Decisions of Todd Margaret, a new US sitcom starring David Cross (the bald one in Arrested Development) as an incompetent, deluded bluffer who, to his astonishment, is mistaken for a sales genius and gets sent to open a UK office for the launch of an unpalatable Korean energy drink.

It had a promising start. The boss (Will Arnett, the unsuccessful magician and womaniser in Arrested Development) was encouragingly sociopathic; there was an amusing scene in which Todd demonstrated his grip on reality by explaining to his cat that he had to go away but would be leaving a month's supply of tuna in the washing-up bowl ("Don't eat it all at once, all right?").

But events in London felt a touch understaffed, too loosely handled, too dependent on Todd's calamities: a mishap trying to get the lid off a jar using steam, a controlled explosion involving his suitcase, an uproarious... um, sales pitch. His blag started to flag. Sharon Horgan (of Pulling fame) was fine as the molecular cook with a heart of gold, but the script neglected her comic gifts. Likewise, Blake Harrison (the tall, thick one in The Inbetweeners), as Todd's factotum, had little to do except laugh loudly at the unfolding hijinks. If only I could have joined in more often.

Inbetweeners: 'We'll top testicle reveal'

Blake Harrison has claimed that the upcoming Inbetweeners film will top the TV show's infamous testicle reveal from the final series.

It was, of course, excruciating, crude and uproariously funny - everything we've come to love from a brilliantly observed British comedy that will be bowing out on a high in three weeks' time. Free of his ridiculous obsession with Carli (Emily Head), Simon's overcome his unfortunate Statue of Liberty haircut and acquired actual human girlfriend Tara (Hannah Tointon); keeping her will be the real challenge.

Helpfully, the ever-loyal Will (Simon Bird) is willing to spend time with Tara's BBF - boring best friend) - if there's the prospect of some - hell, any action at the end of the day.

As The Inbetweeners has confirmed repeatedly and hilariously, the course of both true love and adolescent fumbling never runs smoothly.

Whether it was Will fainting during a gory horror film, Simon appalling Tara's parents after meeting them for the first time or Jay (James Buckley) and Neil (Blake Harrison) encountering a teacher out of his natural habitat, E4's hit series finely captures the continual embarrassment of teenage life.

Not that this third episode ever neared serious territory as The Inbetweeners thankfully avoids the death and depression plots of Skins in favour of a top-notch sight gag involving a motorbike, a new running joke to rival the "Friend!" quip of the first series and revelling in the genuine chemistry between our four loveable leads.

Wayne Rooney wants role on The Inbetweeners

The show's stars Blake Harrison and Simon Bird told the Daily Star: "Apparently, Wayne Rooney and Rio Ferdinand want parts in the show," they said. "And Amanda Holden told us she wants to play a sexy English teacher in the next series."