One day in the spring of 2009, after an off-season practice, Baltimore Ravens linebacker Brendon Ayanbadejo ran into his coach, John Harbaugh, while the two were clearing their trays in the team dining room. Ayanbadejo had just written a blog entry for the Huffington Post backing same-sex marriage and was preparing to make a public appearance with Equality Maryland, a group pressing the state to legalize such unions. Harbaugh, a conservative family man who leads his team in prayer before games, told him he'd read the post. Ayanbadejo braced himself.

Their conversation was civil, but Harbaugh detailed in no uncertain terms why he disagreed with the linebacker's stance. At the end of the talk, though, a funny thing happened: "He congratulated me," says Ayanbadejo, "for taking a leadership position."

The 34-year-old three-time Pro Bowl player, who is biracial (his father is Nigerian) and likens the fight for gay equality to the civil rights and women's movements, was the first straight American professional male athlete to take a public stand in support of homosexuality. And while his coach offered his begrudging respect and some teammates applauded him, a backlash erupted among football fans. After a PSA he shot was posted on a New York Jets fan site, the comments targeting Ayanbadejo rang of homophobia: "When is he coming out of the closet?" asked one. Said another: "Look at the lavender shirt he's wearing. He's obviously gay."

Ayanbadejo wasn't surprised: "I always say the sports world is 10 to 15 years behind normal society." He hears the word faggot used so often in the locker room to slam other players or certain celebrities, it's become just another put-down. And because he favors Louis Vuitton and rocks a pair of oversize ­Dita sunglasses, he is sometimes the target. "It's just part of our macho language," he says. "If I'm wearing something you don't like, you say, 'You fag.'"

In the past few months, a small but steady stream of straight athletes – including the New York Rangers' Sean Avery and the Phoenix Suns' Grant Hill and Jared Dudley – have followed in Ayanbadejo's footsteps by promoting gay rights or tolerance at the prompting of activist groups. "We've known for a long time that if you're going to reach 13- to 16-year-old boys on this issue, our next generation, you need athletes," says Eliza Byard, executive director of the Gay, Lesbian and Straight Education Network (GLSEN), which is behind the Think B4 You Speak campaign to battle antigay language among teens. That doesn't mean she and other activists are always successful in enlisting players. "Some turn us down because it's not their issue," Byard says. "They don't want to make this their battle. They have other issues and don't want to dilute the brand. Some are Catholic and say they are battling with their beliefs."

The issue of gay bullying reached a tipping point last year with several high-profile gay teen suicides. These spurred the internet-based It Gets Better Project, which features celebrities telling gay teens to hang in there. (This May – partly at the urging of a gay fan – the San Francisco Giants became the first major league sports team to join that project, enlisting pitcher Barry Zito and four other players to speak on behalf of the organization.) In the wake of last fall's suicides, Byard contacted Kathy Behrens, the NBA's head of social responsibility and player programs, and pitched her on the Think B4 You Speak campaign and its need for a major sports figure. With the backing of commissioner David Stern, the NBA agreed to support a PSA to run during this year's playoffs. Behrens put out requests to "dozens" of the biggest players in the league or their agents, getting several turndowns, though she says some of that had to do with scheduling. "Some were just not available, but we'll have them in the upcoming print campaign, like [the Nets'] Brook Lopez." For the video, she eventually zeroed in on the Suns' Hill and Dudley, in part because the spot could be filmed in one place that way.

The same day the players shot the video, which shows them preaching against using the term gay as a general put-down, TV cameras caught the L.A. Lakers' Kobe Bryant mouthing "fucking faggot" at a referee, earning a $100,000 fine. The Chicago Bulls' Joakim Noah hurled the same epithet at a fan a few weeks later, costing himself $50,000. Dudley admits that plenty of his teammates – himself included, when he was younger – have used the term from time to time, "when you're mad and trying to get aggressive with someone, like what Kobe did." Still, he says, Bryant's outburst "was shocking to see on TV," and he thinks the fines were warranted.

When the PSA finally aired on May 15, to more than 11 million NBA viewers, both Dudley and Hill saw their Twitter accounts light up – with hostile fans. Hill retweeted some of the choicest responses (among them: "Yo Grant, for realz, that commercial was pretty gay"), stating that "as you can see from my retweets, the PSA was necessary."

May was turning out to be, in the words of Jim Buzinski, co-founder of Outsports.com – an 11-year-old website where gay fans talk sports and where high school and college athletes share stories about coming out – "the gayest month in sports history." The same day that Hill and Dudley's video premiered, their boss, Suns CEO Rick Welts, revealed that he was gay. And earlier in the month, the Rangers' Avery – known as much for assaulting opponents as insulting starlets – appeared in a gay-­marriage PSA.

Brian Ellner, who heads the New York gay marriage initiative of the Human Rights Campaign, the group behind the Avery spot and subsequent ones with Steve Nash and Michael Strahan, had recruited the hockey player through a mutual friend. Avery had won over the gay community earlier in the year when he told a Canadian newspaper he'd gladly stand beside any kid in a locker room who loves hockey and is afraid to come out to his team. "The hardest part about getting athletes to participate is the younger ones are afraid of being teased," says Ellner. "But they are the ones who know we're right because they went to college, and players are starting to come out in college these days. They have gay friends."

British rugby star Ben Cohen learned about the plight of gay youths in a very vivid way. Two years ago, his manager told him that a gay fan, taken by his skills as well as his rugged good looks, set up a Facebook fan page for Cohen that attracted thousands of followers – many of them gay. "It was flattering," Cohen says. But it wasn't until these fans started using the page to share stories about being beaten up in school and mocked on the rugby field and in the locker room that Cohen felt a painful stab of recognition – he hadn't always been politically correct in his own dealings – and the realization that he needed to do something. "A lot of people were telling me about the pain and hurt and anger they've felt for years," he says. "They feel isolated and alone. I felt I had a responsibility."

Today he runs the Ben Cohen StandUp Foundation, an antibullying group. He spent two weeks this spring touring U.S. high schools talking to kids about how to identify gay-targeted bullying and stop it. Among other tactics, he asks the students to sign an antibullying pledge and make up their own slogans to hang on placards around school to fight it. Some of his proceeds go toward helping GLSEN with its education efforts.

All of which raises the question: Are we any closer to seeing an openly gay athlete in a major professional sport? Following Avery's PSA, Charles Barkley went on radio to say, "Every player has played with gay guys," adding, "I'd rather have a gay guy who can play than a straight guy who can't play." Barkley scoffed at the idea, batted around by the talking-point commentators, that locker-room culture would never allow a gay player to come out. And Dallas Mavericks owner Mark Cuban has said the first openly gay athlete would clean up from endorsements and marketing because he would "be an absolute hero to more Americans than you can ever possibly be as an athlete, and that'll put money in your pocket."

Still, so far only retired players have come out. Among the handful of them: 1960s NFL running back Dave Kopay; British-raised NBA center John Amaechi; and Billy Bean, a major-league outfielder from 1987 to 1995. Bean has said he couldn't admit his homosexuality while playing: "Overnight they would have found some way to kick me out, because some dad doesn't want his little kid watching some gay baseball player and saying, 'I want to grow up to be just like him.'"

Outsports' Buzinski thinks the first openly gay player in a major sport will probably come from the ranks of current high school athletes who have grown up with TV shows like 'Glee,' which features a gay football player. "These kids are already out, and their peers accept them," says Buzinski. "All you need is one to go college and then go pro. It will be gradual, no big deal."

In the meantime, activists like Eliza Byard at GLSEN say they will continue to press straight athletes to do their part. At the top of Byard's wish list – though she won't say whether he's been asked or not – is Kobe Bryant. "We're all about teaching people to grow, offering the possibility to grow," she says. "He needs to get to a place where he understands why what he said was wrong and so damaging. He probably needs to reflect more. It would be a powerful moment."