Students from St Andrews University are covered in foam as they take part in the traditional “Raisin Weekend” in the Lower College Lawn, at St Andrews in Scotland, Britain October 17, 2016. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. (Photo by Russell Cheyne/Reuters)

Students from the University of St Andrews jump into The North Sea, as a good luck tradition before exams start on the East Sands in St Andrews, Fife, Scotland on May 1, 2018. (Photo by Derek Allan/Alamy Live News)

Daughter being told off by her mother. (Photo by Peter Dazeley/Getty Images)

Women dressed as nuns pose for pictures during Halloween celebrations in the Shibuya district in Tokyo, Japan October 31, 2015. (Photo by Thomas Peter/Reuters)

Sumo wrestlers compete during the “Honozumo” ceremonial sumo tournament at the Yasukuni Shrine in Tokyo April 3, 2015. (Photo by Thomas Peter/Reuters)

Qian Hao's imported Pekingese dog, Mixiu, runs in a park in Beijing, China, February 8, 2018. (Photo by Thomas Peter/Reuters)

Armed police Taser a man inside the grounds of the Houses of Parliament on 11 December 2018. (Photo by Peter Nicholls/Reuters)

Close up of a couple, with the woman holding the man's knee, underneath a table. (Photo by Peter Dazeley/Getty Images)