The film reunites Talladega Nights director Adam McKay and co-stars Ferrell and John C. Reilly, who play middle-aged slackers who suddenly become step brothers when their parents get married.

Brennan (Ferrell) and Dale (Reilly) become instant rivals and strive to prove who’s boss when they are forced to share a room.

The pair’s relationship soon descends into chaos, and humorous squabbling and continuous fights ensue – including one memorable scene where Ferrell gets his own back on his step brother by messing with his drum kit, in a very unique way (those who have seen the film will know exactly what I mean.)

After several failed attempts at trying to assert who’s in charge, the pair begin to realise that they may be more alike than they had anticipated, and quickly become best buddies, practising karate in the garage, constructing home-made bunk beds – with disastrous results – and standing up to school bullies (who are aged about 11).

The two become allies in a world where they are outcasts, but their friendship begins to unravel when their parents decide to divorce because they cannot agree on how to deal with their sons.

Each blames the other for the split, and decide to go it alone to make something of themselves, so that their parents will fall in love again and reunite.

This culminates with an impromptu musical performance from the pair, Dale on drums while Brennan takes the lead as singer, because he harbours a secret – he has ‘a voice that’s a combination of Fergie and Jesus.’

Step Brothers contains the same off-beat and surreal humour that only Ferrell fans will really get. It’s like a 90 minute-long Saturday Night Live sketch, and had me guffawing out loud on more than one occasion.

And while there are some side-splitting gags in the film, many of the laughs do rely on the electric chemistry present between the two stars, and I think it’s fair to say that had two other actors been chosen for the line-up, the film may not have stood up on it’s own comedic merit.

Subtle humour is not the order of the day here, it’s cringe-worthy, crass and immature – and I loved it. But I think it is hard to ever go wrong when Ferrell is concerned – Stranger Than Fiction being the exception.

And Reilly’s performance cemented his Frat Pack membership for good. I expect to see him popping up in films featuring the likes of Vince Vaughn and Ben Stiller very soon.

I left the cinema with a warm glow after laughing so much, and was still chuckling to myself during the drive home from the cinema when I remembered the hilariously uncomfortable and surreal hug between Brennan and his real brother at the end of the movie. At 30 seconds, it is reason enough to go and see this film.

Featuring a cameo from fellow Frat Packer Seth Rogen (Knocked Up), Ferrell and Reilly shine and really complement each other.