People take part in the annual “No Pants Subway Ride” in Berlin, Germany, January 8, 2017. 

The No Pants Subway Ride is an annual event which was started in 2002 in New York City by Improv Everywhere. The goal of the cheeky stunt is for riders to get on a subway train dressed in normal winter clothes except for pants, and remain serious. No one is to acknowledge the obvious missing wardrobe.

A woman without pants stands on a train platform during the “No Pants Subway Ride” on January 8, 2017 in Prague.

Passengers without trou walk down the stairs into a train station in Prague, Czech Republic, January 8, 2017.

Passengers are seen during the “No Pants Subway Ride” in Prague, Czech Republic, January 8, 2017.

On Sunday participants of the annual “No Pants Subway Ride” pose for a group picture in the snow in front of the Brandenburg gate in Berlin, Germany, where the temperature was 28°F.

People take part in the annual “No Pants Subway Ride” in Berlin, Germany, January 8, 2017. 

No trousers on the Tube! People take part in the annual “No Pants Subway Ride” in London, England, January 8, 2017.

People take part in the annual “No Trousers On The Tube Day” (a.k.a. No Pants Subway Ride) at Kings Cross station in central London, January 8, 2017. 

People without pants descend into a tube station in central London on January 8, 2017. 

People take part in the annual “No Trousers On The Tube Day” at Kings Cross station in central London on January 8, 2017.

People take part in the annual “No Trousers On The Tube Day” (a.k.a. No Pants Subway Ride) on a London Underground tube train, in central London, January 8, 2017.

Passengers take part in the annual “No Trousers On The Tube Day” (a.k.a. No Pants Subway Ride) on board the London Underground, January 8, 2017. 

People participate in the “No Trousers On The Tube Day” on a London Underground train in central London, January 8, 2017.

Steven Blomquist, of Somerville, Mass. (center), speaks with Tim Lewis, of Boston, as they ride a subway train during the annual event “No Pants Subway Ride” Sunday, Jan. 8, 2017, in Boston.

A man without pants dances in a subway station during the “No Pants Subway Ride” in New York on January 8, 2017. 

A subway rider goes pantless during the annual “No Pants Subway Ride,” Sunday, Jan. 8, 2017, in New York. 

A man explains why he is pantless to a woman on the subway platform at Union Square station, after participating in the annual No Pants Subway Ride, Sunday, Jan. 8, 2017, in New York. 

Rina Wang, 20 (left), shares music with friend Tiffany Amaro, 20, as they wait for the R train during the annual “No Pants Subway Ride,” Sunday, Jan. 8, 2017, in New York. 

People without pants travel in the subway during the “No Pants Subway Ride” in New York on January 8, 2017. 

Two men react as a woman puts her boots back on after removing her pants during the annual “No Pants Subway Ride,” Sunday, Jan. 8, 2017, in New York.