ESPN’s Body Issue has celebrated the nude and semi-nude bodies of athletes — from football players to yachtsmen — every year since 2009. And this year, in its 10th annual issue, it made history by featuring a same-sex couple on the cover for the first time.

Professional soccer star Megan Rapinoe and basketball legend Sue Bird are front and center in one of the 2018 Body Issue’s 10 different covers, which all debuted Monday. In the photo, the couple appear nude, with Rapinoe resting her foot on a soccer ball as Bird spins a basketball on two fingers.

Rapinoe, who helped Team USA win a gold medal in the 2012 Summer Olympics, currently plays for the Seattle Reign FC in the National Women’s Soccer League. Bird, who boasts two WNBA championships, four Olympic gold medals and two NCAA titles, plays for the WNBA’s Seattle Storm.

“This is like … Lebron James and Landon Donovan being boyfriends and appearing naked on the cover of ESPN,” said Cyd Zeigler, co-founder of LGBTQ sports site Outsports.

Hudson Taylor, director of LBGTQ sports advocacy group Athlete Ally, agreed, calling the cover a "historic moment."

"With this decision, ESPN has sent a clear signal that it seeks to support and empower LGBTQ athletes," he told NBC News.

Rapinoe is an outspoken advocate for LGBTQ rights and has used her status as a sports star to fight for causes dear to her. In 2016, for example, she caught media attention when she “gave a nod” to former San Francisco 49ers quarterback Colin Kaepernick by kneeling for the national anthem at a Seattle Reign FC game, explaining "Being a gay American, I know what it means to look at the flag and not have it protect all of your liberties.”

Bird has kept her sexuality at a lower profile. In fact, she only came out publicly last July in an ESPN article. In her interview, she recalled filling out a questionnaire ahead of the 2016 Rio Olympics for a magazine article titled “25 things you don’t know about Olympians.”

“I literally had at No. 25: 'I'm gay,'" Bird told ESPN. "And then I just didn't do it. I chickened out.”

But less than a year after coming out publicly, Bird is smiling nude next to her girlfriend on the cover of a magazine that reaches an estimated 17.5 million people.

“It shows you that once somebody comes out …. they see the acceptance that is really inherent in sports today and in our culture,” Zeigler said. “Virtually every single athlete who comes out only regrets that they didn't do this sooner.”

In their interview for The Body Issue, Rapinoe and Bird both acknowledged the importance of LGBTQ visibility and the hope that one day a same-sex couple on the cover a magazine will be a non-issue.

“You want it to just be, ‘Oh, another couple is on there.’ You know, I think for us to be on it is the first step in that direction,” Bird told ESPN.

Rapinoe agreed, saying, “I think neither of us really wants to just do things and be like, ‘We're the gay couple.’ But to have this really unique vehicle to actually do that. To celebrate who we are in our sport, but also the fact that we'll be the first gay couple, is pretty special.”

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