A wedding photo on Facebook leads to the suspension of two Tennessee Freemasons, sparking debate within one of the country’s oldest secret societies.

There’s still a bit of mystery surrounding the Freemasons, a secretive fraternal order dating back to the 17th Century. Their symbols appear on dollar bills and in movies like “National Treasure.”

But there’s no mystery around why Dennis Clark and Mark Henderson joined in 2007. They met the basic requirements for membership: they believed in a higher power and enjoyed charity work.

“We embraced Freemasonry right away,” Clark says. “We loved the idea of the fraternity coming together to promote charity in our community.”

Clark, a corporate leadership trainer, and Henderson, a deputy sheriff, live on a farm outside Memphis. Their lodge, in Midtown Memphis, leans liberal, like the neighborhood in which it resides.

“We were a couple then,” Clark says. “Everybody knew that we were a couple.”

They got to work raising money for charity and renovating the Park Avenue Lodge (539 S. Cooper St.). Soon, Clark was a Master Mason and a rising star in the organization.

That all changed with one Facebook post -- photos of their wedding, taken last June, the same day as the Supreme Court’s ruling on marriage equality.

The snapshots caught the eye of the Grand Lodge of Tennessee in Nashville, the governing body of the state’s Freemasons. Within weeks, charges were brought. Clark and Henderson had violated the constitution’s penal code.

According to the constitution, members are not supposed to “engage in lewd conduct. To promote or engage in homosexual activity. To cohabit immorally in a situation without the benefit of marriage.”

The charges took many Masons by surprise, including Chris Hodapp, a Master Mason and author of “Freemasons for Dummies.”

“Pretty much overwhelmingly most Masons agree that what goes on in a Freemason’s bedroom is none of our business as a fraternity,” Hodapp says.

He says that only two state organizations ban gay men – Tennessee and Georgia. Their rules, he says, pose an embarrassing dilemma for a national organization faced with a declining membership.

“When a young man hears that Masons in a state are throwing gays out or have rules against them, they just see that as the whole organization doing that and not being isolated to a particular area,” Hodapp says.

Paul Rich, a scholar of Freemasonry, says that the society was originally founded as a safe haven for ideas and Enlightenment values.

“It largely eliminated sectarian references and welcomed diversity. Because of that, it attracted prominent people and made an important intellectual contribution,” Rich says, adding that America’s regional ideologies are affecting that spirit. “The Northern lodges are having difficulties being associated with all of this.”

Chris Sanders of the Tennessee Equality Project says that backlash to same-sex marriage, as evidenced by the Kentucky clerk who refused to issue marriage licenses, includes growing reprisals in other areas of society where religious people hold policy power.

“Certainly the Supreme Court’s marriage decision has intensified the fear and the focus among the far right on these kinds of so-called ‘solutions’ to the issue,” Sanders says.

The Grand Lodge of Tennessee is just a few blocks away from the state capitol building, where legislators have tried and mostly failed this year to pass laws as a rebuke to marriage equality. Sanders believes it’s a reaction to openness. In the past, quasi-religious groups like private schools and Freemasons could turn a blind eye to suspected homosexuals.

“But if you’re in a marriage, that’s a public record,” he says. “In a lot of small towns, all marriages are published in the paper every week.”

The Grand Lodge held Clark and Henderson’s trial in Nashville, without the couple present to defend themselves or provide character witnesses.

Grand Master Phillip Hastings, the current leader of Tennessee’s freemasons, did not respond to multiple interview requests. Last November, he outlined the organization’s position of silence in an open letter sent to lodges:

“Brethren, this Masonic matter is to be handled by the Grand Lodge of Tennessee within the State of Tennessee and any further un-authorized discussion on this matter outside of the Tennessee Masonic fraternity will be considered a Masonic offense and will be dealt with accordingly,” Hastings wrote.

Tom Evans, a fellow Mason in Clark’s lodge, was outraged.

“What difference does it make?” he asks. “I don’t care who you love. Doesn’t matter to me. I don’t see why it matters to anyone else.”

But it did matter to Tennessee's leaders in Nashville, who informed members that their Facebook pages were being monitored. Masons could be kicked out for speaking out. The Grand Lodge then threatened to revoke the charter of the Park Avenue Lodge if members spoke to the media.

Evans shrugged when asked if he was worried about punishment.

“If free speech isn’t there, there’s a problem,” he says. “Considering some of the founding members of our country were Masons, that says a lot, where we should be with this.”

The gag order didn’t sit right with Brian McMurray either. His Masonic tattoos reveal a deep devotion for what members call “The Craft.” For him, democratic debate is part of a Freemason’s DNA.

“Just like our leadership changes, so does the opportunity to fine-tune our constitution,” he says. “Constitutions aren’t laid in stone. They’re not supposed to be.”

In March, Tennessee Freemasons will meet to elect a new Grand Master and vote on changes to the constitution. One proposed amendment would remove the ban on homosexuality.

The writer of that amendment can’t be there to argue a case for it, because the writer was Dennis Clark.