The "Arrow" star may play (relatively) serious bad guy Malcolm Merlyn on the superhero show, but, IRL, he is the ultimate cast clown: Hilarious. Larger-than-life. And willing to go the extra mile for a laugh. (We imagine that must come in invaluable on those long days and nights on set.)
Don't believe us? Here are nine times Barrowman went above and beyond to make his co-stars laugh — often through his ridiculously silly antics.
That time he flashed his bum in a "family photo."
Stephen Amell's face, tho.
Those times he stuck his tongue out for a selfie.
You take a picture with John Barrowman, you may be licked.
Those times it became contagious.
Et tu, Katie Cassidy? (JK. We ? this silliness.)
Those times he put his face so close to his co-stars' faces.
David Ramsey doesn't seem to mind.
This may be one of his favorite activities?
Stephen Amell doesn't seem to mind, either.
Those times he set his sights on the expanded "Arrow" universe crew.
Be warned, stars of "The Flash" and "Legends of Tomorrow": No one in the Flarrow universe is safe.
That time he pointed out his co-stars' addictions to social media.
Those who stand in Gorilla Glass houses shouldn't throw stones.
That time he revelled in the awkwardness of the Arrow cast's earlier years.
Technically, we have Stephen Amell to thank for initially sharing these masterpieces with the social media universe (thank you, Stephen!), but we're here to thank anyone who had a part in this compilation.
Those times he broke out the underwear.
Is this his underwear? Photographer/co-star Paul Blackthorne's underwear? A stranger's underwear? Who's to say. Point it: John Barrowman is the silliest, most life-affirming famous person we know.