Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

A woman argues with police officer during a protest in support of jailed opposition leader Alexei Navalny in Ulan-Ude, the regional capital of Buryatia, a region near the Russia-Mongolia border, Russia, Wednesday, April 21, 2021. Navalny's team has called for nationwide protests on Wednesday following reports that the politician's health was deteriorating in prison, where he has been on hunger strike since March 31. Russian authorities have stressed that the demonstrations were not authorized and warned against participating in them. (Photo by Anna Ogorodnik/AP Photo)

A girl walks along former railway tracks in the so- called “Tunnel of Love”, surrounded by arches of intertwined trees, near the Ukrainian village of Klevan, Rivno region, on August 6, 2018. The tunnel of about five kilometres in length is a botanical phenomenon, which became a cult place for tourists and couples in love. The tourist legend says that wishes of couples in love will come true, if the couple passes through the tunnel. (Photo by Sergei Supinsky/AFP Photo)

Photographer Ma Hongjie has spent 11 years documenting families in various parts of China for his upcoming book The Family Belongings of Chinese People. Here: a couple with their belongings and vegetables in Hebei Huailai county. (Photo by Ma Hongjie)

A couple joke as they walk on the beach on August 22, 2018 in Wonsan, North Korea. (Photo by Carl Court/Getty Images)

A couple kisses during a LGBT Pride parade in Oviedo, northern Spain, June 28, 2016. (Photo by Eloy Alonso/Reuters)

A couple embraces at the San Fermin festival in Pamplona, northern Spain, July 10, 2016. (Photo by Eloy Alonso/Reuters)

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