When it comes to odd behavior in the bathroom, though, comparing penis sizes is not the half of it. Hall of Fame pitcher Greg Maddux used to mosey up to rookies in the shower, engage them in conversation and, while pretending to listen to them talk, secretly pee down their legs. (Players describe so much peeing in showers that it's a wonder teams even bother to install urinals in locker rooms.) And many teams use the shower as Maddux did, to establish hierarchy. On the Titans, Jason McCourty always takes the last showerhead on the left, while Bernard Pollard likes the pressure and temp of the middle shower. "If anybody is in it," warns Pollard, "they are going to move."

Besides marking territory, interaction in showers can go from the occasional naked dance-off to towel-snapping, ass-slapping and the miming of various sex acts.

In a literal sense too, the shower is often the filthiest place in the stadium. There are tales from Oakland of raw sewage seeping up through the shower drains. Breakouts of MRSA, a form of staph infection resistant to many antibiotics, have made hitting the showers in Cleveland and Tampa a matter of life and death. Purposefully spartan in design, team showers are usually a simple open-ended 300-square-foot rectangle lined with plain tile and 15 or so shared industrial spigots -- they're designed so that no one wants to spend an extra second in there. It's almost always crowded, uncomfortably steamy and dangerously slippery. Some sociologists hypothesize that one reason teams don't provide individual showers is that the more privacy you provide, the easier it is for behavior to escalate from homosocial to something sexual.

As a culture, we have always struggled to reconcile the idea that such an intimate, homoerotic ritual is being performed by men who epitomize the culture's heterosexual ideal. "A bunch of athletic men, all naked together, lathering themselves up and bonding in a shower room -- I mean, that's the beginning of a gay romance novel," says Scott Cooper, a former linebacker for Augsburg College in Minneapolis who in 2013 officially came out to his teammates before his senior season. "But the reality is that it smells like s--- in there, you've got big, heavy linemen with their perpetual BO and all you really want to do is rinse off, get clean and get out of there without touching some guy's smelly ass or stepping in anything gooey."

Still, isn't a gay player's showering with straight teammates the same as a straight man in a locker room full of attractive women? Davis says no, and when speaking to teams he asks straight players to imagine that the women in their locker room fantasy are, instead, their moms, sisters, aunts and other family members. It's the same for gay players, he says: They view teammates as family. They're not going to be attracted to their brothers. And vice versa. Players, he says, find the theory comforting, if not entirely foolproof. "To be blunt, I never worried about popping a boner in the shower," says Cooper. "It's just not a romantic place at all."

In St. Louis, all Sam will say is that the Rams have provided a "comfortable environment." His teammates' reaction to showering with the first openly gay man in NFL history can best be summed up as one collective yawn. "Look, guys shower together," says Rams linebacker Jo-Lonn Dunbar. "And Sam's been showering with guys forever. We haven't had any issues, and he's been here a month, and I'm pretty sure he's washed his tail in the last month. I don't know what people think or what their perception is of a team shower, but it's really not that cool. You just kind of get in there and get clean and just drop drawers. If everybody hasn't moved on from this already, they should now."

THE LINK BETWEEN the regenerative properties of water and the masculine ritual of bathing together is so strong for teams that after integrating the major leagues, Jackie Robinson still felt like an outsider in his own clubhouse until a fellow Dodger coaxed him to start showering with the rest of his Brooklyn teammates. Today, when a player rushes out of the practice facility without dropping drawers with his teammates, he'll get teased for relying on what's jokingly called a "shower pill" until he relents and gets under the water.

The bond runs so deep that at this year's Super Bowl, when Seahawks quarterback Russell Wilson and several teammates wanted to rejuvenate during halftime, they all stripped naked and jumped into the shower at MetLife Stadium while the rest of the world bathed in Bruno Mars. Ninety minutes after the final whistle, receiver Golden Tate was back in the shower, this time celebrating with the presumably waterproof Lombardi trophy.

It's not just locker room etiquette that has changed; the very definition of masculinity has evolved. Once, presenting as a member of the heterosexual athletic hegemony required acting homophobic. Now, many athletes say, being a man's man in the sports world requires supreme confidence -- and to show it by respecting everyone, even when the only thing you're both wearing are shower flip-flops. "I don't know exactly how the definition of masculinity has changed over the years," says Rams defensive end Chris Long. "But as a 29-year-old, my definition of being a man is treating people with respect and having the courage to accept differences in others no matter what. And someone's sexuality is just not at the top of my list when I'm deciding how to treat people and conduct myself."

So perhaps it's actually a sign of change that Michael Sam's new teammates are already picking on him, just like they would any other rookie. "We're usually just in there talking about practice or something, like, 'Mike, you kinda got your ass beat out there today, you know what I'm saying?'" says Rams wideout T.J. Moe, who also played with Sam at Missouri. Adds linebacker and team captain James Laurinaitis, "You're not a part of the group if you're not being made fun of. I have gigantic ears, and I'd feel like people here didn't like me anymore if no one made fun of my ears. It's the exact same with Michael. He wants to be clowned on and made fun of just like everyone else. And that's what has happened."

At Augsburg, Cooper never felt more happy, or accepted, than when he and his teammates -- the born-agains and the badasses alike -- stopped staring at the shower ceiling after he came out and went back to relentlessly making fun of one another. At first, they snickered at all of his hair and skin products. Then they started borrowing them. When a teammate asked him if he had been tanning, Cooper yelled back, "Oh, are you staring at me naked?"

They were even able to play the darkest shower taboo for laughs. "Early on I had to tell my teammates, 'You can make fun of it, you can joke about it, it's OK: Come at me,'" says Cooper. "So then any time we'd be in the shower and someone would drop their soap, everyone would yell, 'Uh-oh, Coop!' and we'd all laugh."

That kind of teasing camaraderie has always been the rule, rather than the exception, when it comes to the team shower -- no matter players' sexual orientation. Case in point: One of the most popular ways of hazing NFL rookies these days is by repeatedly splashing them with shampoo and liquid soap right as they step out of the shower, forcing them to go back inside to rinse off.

So all this time the sports world has been trying to convince us that real men would never allow gay players in a space as intimate and sacred as the team shower.

But the naked truth is, whether they realize it or not, they won't let them out.

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