Justin Bieber has been winning us over with a slew of endearing appearances lately [1], and his latest viral video with Jimmy Fallon [2] is a nice addition to the list. The singer, who has been promoting his new album, Purpose, nonstop all week, joins the Tonight Show host for a hilarious clip featuring their elaborate secret handshake — one that includes fake punches, finger snaps, and even a "butt tap." Watch the funny video above now, then see Justin's latest carpool karaoke segment [3] with James Corden.