The "Sorry" singer joined Posty at the Hollywood Bowl for the second and final night of his L.A. shows. Sitting close to each other, Bieber grabbed the mic and began to emotionally tell the crowd how much their friendship means to him.
"I love you with all my heart," the singer tells Post. "I’m rooting for him. Everyone give it up for Post Malone!"
Once the emotions were out, it was a non-stop party.
Fans went nuts when the two began singing Post's song "Deja Vu," which features JB. The two continued to bro down backstage and Bieber even posted a pic of them drinking Bud Lights.
"Your (sic) a beautiful person Posty!" he wrote in the caption. "Truly an honor to know you my brother!"