It's no secret that Justin Bieber and Post Malone are the best of friends, having formed a close bond in 2016, the same year JB was featured on his pal's album, Stoney. Despite their hectic careers, Post and Justin always find time to do something fun together, whether that's going to parties with friends, playing video games, or simply making music together.

Post, who is one of the most recognizable rappers in the world, surprised fans when he labeled Justin his "brother"; some argued that their bromance was somewhat unexpected. When they first started hanging out together, certain Bieber fans questioned what the duo could possibly have in common.

Aside from his wife, Hailey Baldwin, Post is possibly Justin's closest friend in Hollywood, but what else is there to know about this 'doting duo'? Here are 15 little known facts you should know.

15 Justin and Post Malone’s Bromance Started in March 2016

From what fans have gathered, Post Malone’s friendship with Justin Bieber didn’t commence until March 2016. This was when Justin uploaded a photo of himself with the Texas-born rapper/singer-songwriter to Instagram.

The two appeared to be having a conversation while smoking a cigarette, and the caption read: “silly people’s.” The rest was history after that.

14 Justin Personally Chose Post Malone To Be His Opening Act On Tour

When Justin was putting together his Purpose Tour in support of his fourth studio album, he personally hand-picked Post Malone to be his opening act on the North American leg. Post Malone was still riding high from the success of his song, "White Iverson", so the new business relationship as touring buddies seemed to make perfect sense.

13 Post Malone Considers Justin Bieber His Brother

Post Malone has often referred to Justin as his brother, despite the fact that their friendship only blossomed in 2016. It would seem that the two have enough things in common to think of each other as coming from the same family. This explains why the two always speak so highly of one another in interviews.

12 They Don’t Talk About Their Views On Religion

After it was claimed that Bieber had canceled his tour to focus his attention on Christ and dedicating his life to his religion, Post told Rolling Stone (in a revealing interview) that his friend had apparently gifted his church with a whopping $10 million. Post described the Bieb's church as “a total cult,” adding that “we don’t talk about this stuff.”

11 They Share The Same Humor, Hence Why They Get Along So Well

Fans will have already come across a number of silly photos that Post and Bieber have posted of one another on social media. However, when Post playfully choked his pal in one of the snaps, some believed the two had gone too far with their joking antics.

Post Malone later issued a statement, saying: “He’s my big brother and we like to roughhouse… if we was fighting someone would have done something instead of just sit around while the beibs [sic] gets chokeslammed.”

RELATED: 20 Photos That Change The Way We See Justin Bieber

10 Justin Has Heavily Supported Post Malone’s Career

Following the release of Post Malone's second studio album, Beerbongs & Bentleys, in August 2018, Justin was one of the first celebrities to congratulate Post Malone on the release of yet another amazing record.

"Proud of my brother @PostMalone on his new album,” Justin said in a tweet to his millions of fans, clearly indicating his support for his pal’s career.

9 Justin And Post Malone Were Bro-ing Out At Coachella 2018

In 2018, while Bieber was still on hiatus from music, the two decided to hit up Coachella with a few of their friends, and it goes without saying that the two had a blast partying it up with while enjoying some of the biggest songs of the year.

Justin was also in tow to see Post take to the stage and perform during his set at the festival. The Biebs watched from the crowd.

8 Justin Gave His First Performance Since Canceling His Tour At A Post Malone Concert

On June 29, 2018, Justin gave his first live performance after his tour cancellation, as he joined Post Malone onstage at his concert at the Hollywood Bowl. The two stars sang their collaboration, "Deja Vu". Before leaving the stage, JB was heard saying: “I love you with all my heart… I’m rooting for him. Everyone give it up for Post Malone!”

7 Post Malone Opted To Be The Flower Boy At Justin’s Wedding

After Justin popped the question (he asked Hailey Baldwin to marry him in the summer of 2018), Post Malone made it clear he wanted some kind of role in the couple’s wedding, telling TMZ that he was open to a number of positions. “I’ll be the flower boy—is that a thing?” he joked.

RELATED: 20 Little Known Facts About Scooter Braun And Justin Bieber’s Relationship

6 They Are Both Signed Under Universal Music Group

Over the summer of 2015, Post had signed a major record deal with Republic Records. This followed the release of his song, "White Iverson", which took the charts by storm across the globe.

Republic Records is part of Universal Music Group, which also owns Def Jam, which is the label that Justin has been signed to throughout his career.

5 Post Malone Planned To Throw Justin A Bachelor Party After Justin Proposed To Hailey Baldwin

While it’s unclear whether or not this took place, Post Malone stressed that he would throw Justin a bachelor party right before Bieber tied the knot with Hailey. “We’re gonna do some fishin’, we’re gonna do some hangin’ out,” he revealed, after being asked to elaborate about what the party would entail.

4 Their Friendship Is Adored By Millions On Instagram

Fans absolutely adore the friendship between Post Malone and Justin Bieber. Even though their photos have left people concerned in the past (with Justin appearing to grab Post’s throat, and Post doing something similar to Bieber), the two are the best of buds. They both deem it as nothing more than innocent playfighting behavior.

RELATED: 20 Facts About The Bachelor You Didn't Think You Needed To Know (Until Now)

3 They Have Collaborated Together In The Past

Post Malone was fortunate enough to scoop up a collaboration with Justin on his debut album, entitled Stoney. The song is called "Deja Vu" and was released to the public on September 6. It charted in the US, UK, New Zealand, and Scotland, and went on to sell well over 1.5 million copies.

2 Post Malone Is One Of Justin’s Closest Friends In Hollywood

Justin Bieber doesn’t hang around as many celebrities these days as he used to. Just a few years ago, it wasn’t uncommon to see JB with the likes of the Kardashians, Jenners, Lil Za, and Lil Twist. These days, it seems Justin has narrowed down his circle of friends to people he shares a genuine bond with.

RELATED: Justin Bieber Spent Most Of 2019 Battling Lyme Disease

1 They Often Trade Compliments With One Another

When Post Malone was on the H3H3 Podcast in June of 2017, Justin called in, just to have a back-and-forth conversation with his pal for one full minute. Each told the other that they had “the best smile in the game.” It was rather random, but to see that Justin has the time to call in and show love to Post on a podcast shows that he truly appreciates him.