A female Marine prepares to throw a practice grenade during Marine Combat Training (MCT) on February 21, 2013 at Camp Lejeune, North Carolina. Since 1988 all non-infantry enlisted male Marines have been required to complete 29 days of basic combat skills training at MCT after graduating from boot camp. MCT has been required for all enlisted female Marines since 1997. About six percent of enlisted Marines are female. (Photo by Scott Olson)

In this 1997 photo released by the International Fund for Animal Welfare, a seal hunter, right, threatens a cameraman with a knife during the filming of a seal hunt in the Gulf of St. Lawrence, Canada. “Huntwatch”, a documentary by the organization about the fight to end commercial seal hunts, premieres in September 2016 on Discovery. The producers say it includes grainy but powerful archive footage that had languished in the basement of the group’s headquarters on Cape Cod for nearly five decades. (Photo by Richard Sobol/IFAW via AP Photo)

An American flag is visible in the windows of the cupola aboard the International Space Station. Thanks to a bill passed by Texas legislators in 1997 that put in place technical voting procedure for astronauts – nearly all of whom live in Texas – they have the ability to vote from space through specially designed absentee ballots. To preserve the integrity of the secret vote, the ballot is encrypted and only accessible by the astronaut and the county clerk responsible for casting the ballot. (Photo by NASA)

Paris Photo is the largest international art fair dedicated to the photographic medium and is held each November at the historic Grand Palais in Paris, France on November 7, 2018. Since 1997, the Fair’s mission is to promote and nurture photographic creation and the galleries, publishers and artists at its source. The 22nd edition of Paris Photo will takes place Thursday, November 8 through Sunday, November 11. (Photo by IBO/SIPA Press/Rex Features/Shutterstock)

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

Three members of English pop group The Tremeloes; Chip Hawkes, Alan Blakley and Dave Munden, kissing their brides; Carol Dilworth, Lyn Stevens and Andree Wittenberg, in Trafalgar Square, London. (Photo by Wesley/Getty Images). 1967

Models blow kisses on the runway wearing Liliana Montoya swimwear at a FUNKSHION fashion show during Swim Week, Sunday, July 23, 2017, in Miami Beach, Fla. (Photo by Lynne Sladky/AP Photo)

Paris Jackson, left, and Caroline D'Amore kiss in the press room at the MTV Video Music Awards at The Forum on Sunday, August 27, 2017, in Inglewood, Calif. (Photo by Jordan Strauss/Invision/AP Photo)