Justin Bieber and Jaden Smith are the definition of a Hollywood bromance that has lasted for over a decade. Being famous from such a very young age must've bonded the two, as Bieber rose to stardom thanks to YouTube in 2008 and Jaden Smith was only eight when he made his film breakthrough in The Pursuit of Happyness with his father, Will Smith.

That said, there's so much to tell about the dynamic between Justin and Jaden. How did "Never Say Never," the pair's ultimate collab, come about? Are they still good friends? Is it true that Jaden was once refused from Justin's birthday party because he was underage? The answers to these burning questions are here!

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8 Justin Bieber & Jaden Smith Linked Up For 'Never Say Never' In 2011

Justin and Jaden first met in the early 2010s for "Never Say Never," an uplifting pop tune with a hip-hop flavor. The song itself serves as the official soundtrack of Jaden's then-forthcoming film Karate Kid, as well as Justin's sophomore remix album. The song was a classic 2010s pop hit, peaking within the top ten in many international charts. It also helped the film to earn $359 million out of its $40 million budget.

7 The Original Version From The Original Artist Was Much More Sexual

However, the original version of the song is so much more sexual. The demo, titled "Sexy Together," was recorded by Travis Garland and produced by The Messengers producing and songwriting collective. Soon after, the original writers, plus Kuk Harrell, Nasri, and Omarr Rambert, rewrote the song and featured Jaden's rap verse.

"I be tryna chill They be trying to side with the thrill," Jaden raps. "No pun intended / Was raised by the power of Will."

6 Justin Once Said He Wanted 'To Be As Cool' As His Pal

It's no secret that the two share many wholesome moments on social media. This happened in 2017 when Biebs posted a photo of his best pal casually walking and sporting a Frank Ocean blonde look and an Iron Maiden tee, suggesting that he wants to embody the level of swag as Jaden.

"Can I be as cool as you are please," he captioned, posting for his 189 million followers on Instagram. Up to this writing, the snap has amassed over two million likes!

Related: Why Does Jaden Smith Use Fake Tattoos?

5 In 2013, Justin Said He Had The 'Worst Birthday' As Jaden Was Rejected From London Nightclub

However, things haven't always gone smooth for the pair's friendship. Back in 2013, the pop star turned 19 and hosted a party at Cirque Du Soir in London, England. It all went south after his pal, who was still 14 at the time, was rejected from entering because he was underage. Justin's then-love interest, Ella-Paige Roberts Clarke (17), was also refused entry.

Later on, as Daily Mail reported, the paps spotted them heading off to the nearest McDonald's before retreating to their hotel. "Worst birthday," the singer expressed his frustration in a now-deleted tweet.

4 They Shared This Wholesome Bromance Moment On Instagram In 2018

In 2018, Justin and Jaden had another wholesome exchange on Instagram. The powerhouse singer joked that he's Jaden's boyfriend in his comment on the actor's then-latest Insta pic which features him singing into a microphone.

"Thought I was your boyfriend," Biebs wrote, presumably referring to Jaden calling Tyler, the Creator his "boyfriend" on the stage earlier at Flog Gnaw Carnival music festival in Los Angeles on November 12, 2018. "You know that you are," Jaden later responded.

Related: This Is How Fans Really Felt About Justin Bieber’s Long Hair

3 The Two Are Still Actively Collaborating With Music

Ten years after "Never Say Never," the pair reunited musically once again. Jaden tapped his best pal for "Falling for You," one of the singles of his then-forthcoming EP CTV3: Cool Tape Vol. 3 last year.

"I was thinking 'Man, I want Justin on this song so bad,'" the After Earth actor stopped by Apple Music to sit down and chat with Ebro Darden about the song's creative process. "And I didn’t tell him I wanted him on the song until 10 months into me working on the song. I worked on it for almost a year before I played it for him one time."

2 Last Month, Justin Wished Him A Happy Birthday & The Two Headlined SoFi Stadium's 'Freedom Experience'

It comes as no surprise that Justin feels strongly about Jaden. Just this summer, the "Sorry" singer took to Instagram to wish Jaden a belated happy 23rd birthday, along with a heartfelt caption. In July, the two also linked up to head SoFi Stadium's "Freedom Experience" event, hosted by Jason Kennedy.

"Happy birthday to my brother and best friend," Justin captioned, alongside two kissing emojis. "Thank you for your constant efforts in making this world a better place! I am so inspired by you. Keep being the leader and innovator that you are, we all follow your lead."

1 Their Relationship Remains As Tight-Knit As Ever

Not only do they wish each other a beautiful happy birthday every year, but they still go out to dinner together. Last year, Jaden Smith was joined by several friends, including Hannah Montana actor Moises Arias, and Justin and Hailey Bieber, for a cheeky dinner on Monday night in Malibu. Earlier that day, the two also spent some time together with friends at the beach.

Next: Justin Bieber Feels 'So Blessed' On Weekend Away With Wife Hailey