Yes, you read that right (and no, this isn't Stefon speaking). The star of cinematic treasures Forrest Gump, Cast Away and Sleepless in Seattle busted a move to Montell Jordan's 1995 jam – and the Biebs got it all on camera.
"Haha Tom Hanks singing 'This Is How we do it' dressed like a Rabbi lol #thatdancetho," Bieber, 20, captioned his Instagram video of the actor getting down on the dance floor as the crowd goes wild.
What event could possibly bring Hanks, 57, and the pop singer together? The wedding of Bieber's manager Scooter Braun and cancer activist Yael Cohen, who tied the knot in Canada over the weekend.
Ed Sheeran, Carly Rae Jepsen and Sophia Bush also posted photos from the star-studded nuptials, but it's safe to say Hanks and Bieber's clip takes the (wedding) cake.
Watch the video – already liked by more than 360,000 Instagram users – below: