Jimmy Fallon has introduced quite a few ridiculous games on The Tonight Show, but this latest gag maybe his most outrageous. Joined by his muscleman guest Terry Crews, the two sang the Paul McCartney and Stevie Wonder classic hit Ebony and Ivory. Without shirts. While flexing their muscles to the rhythm.

Of course, Jimmy had to be superimposed onto a ripped body for his flexing, but Crews impressed the crowd with his own actual six-pack. They call this skit, ‘Nip Syncing.’ Sorry Jimmy, but WTF?