Best celebrity Twitter and Instagram posts of the week: Simon Cowell, Rebel Wilson, Ben Stiller

Simon Cowell shows off his sweet side when it comes to son Eric on Twitter while we got an exclusive look at what Jared Leto's Joker will look like in upcoming movie Suicide Squad.

Pitch Perfect's Rebel Wilson visits the Louvre in Paris on the promotional tour of the film's sequel and Justin Bieber finally cuts that shaggy blond hair.

IBTimes UK looks back at all the social media fun from the past week...

Ben Stiller confirms Justin Bieber will appear in Zoolander 2

There has been a handful of celebrities that Meet The Parents star Ben Stiller has announced will be featuring in the upcoming sequel to 2001's Zoolander but this week he told Beliebers everywhere the Baby singer was part of the ever-growing roster with the helping hand of this funny post.

The black-and-white image saw the pair gazing into each other's eyes attempting their best blue steel pouts. It was later shared again by Bieber, who made sure his fans knew that that is not his real hair by hashtagging "#itsawignotmynewhair".

David Ayer reveals the first look at Suicide Squad's Joker

Jared Leto has been transforming himself in preparation to play The Joker for a long time now; first cutting his iconic ombré and then dying it peroxide blonde but fans were not expecting to see him in [almost] full costume until the movie came out in 2016.

However, director David Ayer took to Twitter on 25 April to simultaneously give DC fans a sneak peak as well as wish the iconic character a happy 75th birthday.

Rebel Wilson 'louvres' Paris

Pitch Perfect 2 is set to come out in the UK on 15 May and to promote her latest film, Rebel Wilson has been travelling around Europe to talk about the movie.

We love this rock star photo of her set to the backdrop of none other than French museum the Louvre. Looks like the Aussie actress has thoroughly enjoyed being a tourist these past few days.

Jimmy Fallon posts video of Jeremy Renner as Hawkeye covering Ed Sheeran's Thinking Out Loud

Jimmy Fallon is renowned to be able to get his celebrity guests to participate in comedy skits or silly games when they are on his chat show. But Jeremy Renner's rendition of Thinking Out Loud as his Avengers: Age Of Ultron character was a cut above the rest.

He sang all about Hawkeye's skills and how hard it is to be in a gang with the likes of Thor, Captain America and Hulk with their obvious superpowers. It is OK Hawkeye, we still see you as an important of the team.

Cameron Crowe shares a selfie of his Aloha cast

Cameron Crowe's Aloha will be released in May in the US (September in the UK) and tells the story of Brian Gilcrest, a celebrated defence contractor who unexpectedly falls in love with the toughened Air Force watchdog assigned to him while also reconnecting with his ex-girlfriend.

The film stars Bradley Cooper, Emma Stone and Rachel McAdams and director Crowe chose to share this behind-the-scenes snap of his three leads looking all sun-kissed and smiley, back in their filming days in Honolulu.

Kim Kardashian discovers the power of a photograph

Who would have thought a photograph would give away so much? Despite having coloured her hair back brunette weeks previous to this tweet, it seemed as though Kim Kardashian had a blonde moment when she seemed to forget photos would actually show her what she was wearing rather than it simply being a credit to her amazing memory skills.

Justin Bieber FINALLY reveals his short hair

He has been experimenting with his hair for a few months now, growing it long and even dying it peroxide blond, but Justin Bieber has gone to back to the look his fans know and love. He teased the idea of a hair trim on 22 April as his hairdresser posted an image of hair on the floor.

He was then spotted by paparazzi later on that day with a towel over his head. As you can imagine, his fans went bonkers. But haters of his alternative look must have been jumping for joy when the Never Say Never singer eventually debuted his fresh new cut.

YouTube star Todrick Hall uploads his flawless Beyoncé mash-up

Todrick Hall has covered Beyoncé many times in his popular YouTube videos but this one has got to be our favourite to date. Hall filmed four separate videos to achieve all the harmonies heard in the video, as well as piecing together the perfectly timed choreography.

He manages to feature Queen B's entire discography, which is over 70 songs, in just four minutes. We are seriously impressed.

Robert Downey Jr posts a sarcastic, sassy selfie

Robert Downey Jr only got his Instagram account three weeks ago but the 50-year-old has already mastered the art of selfie taking.

Ever the diva, the Avengers: Age Of Ultron star saw an opportunity for a joke when this sign told him there was to be no smoking in the room he was in. Indicating that he was "smoking" himself, Downey Jr captioned the photo of himself and the sign: "Too smoking for this room. Better leave."

Well, we can only assume he was talking about himself and not the random guy sitting in the corner.

Simon Cowell watches The Lion King with his son Eric

It appears as if television's former Mr Nasty has well and truly gone soft when it comes to his one-year-old son. Tweeting how they had both had enough of watching Disney's The Jungle Book, the pair were now moving on to The Lion King.

His super-cute photograph showed the music mogul having a little snooze while snuggled up to Eric as he watched Timon and Pumbaa's antics on screen intently.