Dozens of commuters stripped down and hopped on a train for the annual No Trousers Tube Ride today (7 January).
But why, you ask? The aim is to make people laugh and spread a little joy.
No Pants Subway Ride began as a small prank in New York in 2002 and has since spread to over 60 cities around the globe.
This is the ninth annual No Trousers Tube Ride in London.
Tom Hayes wrote on Twitter: ‘It may seem odd to you, but it’s a genuinely fun event.
‘It brings smiles and silly giggles – which lets face it, we could all use more of at the moment,’ he said.
‘It’s tons of fun’
He was one of a handful of guides today, leading the charge for groups of trouser-less people.
Another commuter was Simon Champ. He told Gay Star News: This is the second time I’ve done the No Trousers Tube Ride.
‘It’s tons of fun and a great laugh. It’s all to brighten up what is essentially a dull month,’ he said.
Take a look at some of the best photos from the day: