BERLIN (AFP) - A man lounges across two seats on a crowded Berlin train, oblivious to his surroundings, until the two women opposite him suddenly spread their legs, revealing a message on their trousers: "Stop spreading".
Feminist activists Elena Buscaino and Mina Bonakdar are on a mission to stamp out manspreading - the habit that some men have of encroaching on adjacent seats without consideration for their female neighbours.
"It is perfectly possible to sit comfortably on public transport without taking up two seats by spreading your legs," said Ms Bonakdar, 25.
The two female activists' provocative stunt is part of a wider initiative called the Riot Pant Project featuring slogans printed on the inside legs of second-hand trousers.
Ms Bonakdar and Ms Buscaino, both design students, came up with the idea as a way of helping women and LGBTQ people reclaim public spaces often dominated by men.
As well as "Stop spreading", the project's slogans include "Give us space" and "Toxic masculinity" - which, in a nod to the behaviour of those they are aimed at, are only revealed once the wearer shows their crotch.
"It is only through imitation that the interlocutor understands the effect of his or her behaviour," said Ms Buscaino, 26.
But she also admits that very few men immediately change their posture when confronted with the slogans, as observed by Agence France-Presse on the Berlin underground.
"They are often just astonished that women are behaving like that in front of them," she said, but she hopes the project will at least give them food for thought.
For Ms Bonakdar, simply wearing the trousers in itself allows women to "feel stronger and gain confidence".
Although it may seem trivial to some, the problem of manspreading has existed almost since the dawn of public transport.
"Sit with your limbs straight, and do not with your legs describe an angle of 45, thereby occupying the room of two persons," the Times of London advised as early as 1836 in an article on bus etiquette, as cited by Clive D.W. Feather in "The History of the Bakerloo Line".
The term "manspreading" was coined in 2013 when New York subway users began posting photos of nonchalant male passengers and their contorted neighbours on social media.
According to a 2016 study by Hunter College in New York City, 26 per cent of male subway users in the city are guilty of the practice, compared with less than 5 per cent of women.
The US metropolis was one of the first in the world to try to start curbing the behaviour.
In 2014, the Metropolitan Transportation Authority launched a campaign featuring signs with the message: "Dude... Stop the Spread, Please".
Similar campaigns have also since been launched in South Korea, Japan, Istanbul, and Madrid, where manspreading has even been punishable with fines since 2017.
The campaigns have sparked a backlash on the Internet, with men citing biological differences as a way of justifying the need to spread their legs even if no scientific study has yet proven their argument.
Instead, the phenomenon has more to do with "gender roles" in society, Dr Bettina Hannover, a psychologist and professor at the Free University of Berlin, told AFP.
"Men sit more possessively and indicate dominance with their seating position, while women are expected to take up less space and above all to behave demurely," she said.