Yayo Grassi, left, and his partner, Iwan, meeting with Pope Francis at the Apostolic Nunciature on Sept. 23. (Marisa Marchitelli)

Yayo Grassi’s phone rang in early September.

“Is this Obdulio?” said the caller, using a nickname given to Grassi 50 years earlier by a high school teacher.

“Who is this?” said Grassi, spooked.

“Who else calls you ‘Obdulio’?”

“Only one person,” Grassi said, “and I’m not going to talk until you identify yourself.”

“This is Jorge Mario Bergoglio,” the pope said, using his given name, according to Grassi. “I would like to give you a hug when I go to D.C.”

That hug — between the leader of the Catholic Church and a lifelong friend who is gay — came Sept. 23 at the Apostolic Nunciature during the pope’s first visit to the United States. Grassi put on a bright-blue checked blazer, brought along his boyfriend of nearly two decades, and embraced his former teacher in a sunlit parlor of the Vatican embassy.

This quiet meeting came to light Friday, after the Vatican — responding to questions about the pope’s meeting with Kim Davis, the controversial Kentucky county clerk jailed for refusing to approve same-sex marriage licenses — clarified that hers was only one of many “brief greetings” within a larger audience on his visit to the Vatican’s embassy.

“The only real audience granted by the pope at the Nunciature,” said the Rev. Federico Lombardi, head of the Holy See press office, “was with one of his former students and his family.”

Pope Francis had a private meeting with a same-sex couple during his visit to Washington, D.C. in September. The pope, who used to be a teacher, met with a former student and his partner. (Marisa Marchitelli)

That student was Grassi, 67, and that family was his boyfriend, Iwan.

The embassy visit lasted about 15 minutes and consisted mostly of pleasantries.

“We have taken up too much of your time,” Grassi said, after the pope blessed three of Grassi’s friends and asked them to pray for him, in Spanish in a video of the pope's visit.

“No, by God,” the pope said, “thanks for coming by.” He then hugged Grassi, kissed his boyfriend twice on the cheek and said goodbye to the group.

Grassi and Francis first met in their native Argentina, at Inmaculada Concepción high school in Santa Fe, where the future pope was a teacher.

On Friday afternoon, a few hours after CNN broke the news of his papal audience, Grassi was cooking Argentine-style beef tenderloin at his home in LeDroit Park in Northwest Washington. His cellphone and land line were ringing off the hook.

A team from ABC News was at the door in the rain, but Grassi politely shooed them away.

The caterer had to prepare a dinner for 25 at the Phillips Collection by 4:30 p.m.

But he was willing to chat for a couple of minutes about a friendship that he considers sacred. It began in 1964 and 1965, when Bergoglio taught Grassi Argentine literature and psychology.

“He was an extraordinary teacher and a great mentor,” Grassi said, turning off his buzzing iPhone and lighting a Dunhill cigarette. “He kept pushing my horizons, to oblige me to keep looking. He asked me to put on the skin of my fellow man, to feel their pain.”

Grassi’s mother used to cook gnocchi for Bergoglio when he visited the family home in Parana. Grassi, who learned to cook from his mother, has operated his own D.C. catering business since 2005. Before that he was the director of catering for the National Gallery of Art. Grassi moved to the District in 1978 and lost touch with his teacher until 2008, when then-Cardinal Bergoglio granted him an audience in Buenos Aires.

Bergoglio became pope five years later, and Grassi reached out to Francis ahead of his first trip to the United States. A meeting was planned for Sept. 23.

When news broke this week about Davis’s visit, Grassi decided to speak out.

“Although I didn’t know any details, I knew immediately that [Francis] had nothing to do with this, that this was arranged by other people without telling him the real character” of Davis, Grassi said in his kitchen, checking on the tenderloin. “I received, from friends of mine, a lot of quite disturbing mail, telling me that: ‘This is your pope, look what he did,’ and ‘He’s a coward.’ And my defense is, we don’t know anything. Just wait until things come out. And I’m extremely pleased that I was right. And I never had any doubt that I was right.”

The Vatican was far less definitive, and it described the meeting as a routine visit between friends.

Grassi, Lombardi said, “had already met other times in the past with the pope” and asked to introduce “several friends to the pope during the pope’s stay in Washington, D.C. As noted in the past, the pope, as pastor, has maintained many personal relationships with people in a spirit of kindness, welcome and dialogue.”

The Vatican on Friday similarly played down the significance of the Davis visit, which opponents of same-sex marriage had hailed as validation of their cause. The Vatican said the meeting was initiated by the papal embassy — not Francis himself — and was not meant as an endorsement of all of Davis’s actions and views.

In 2010, when Francis was still a cardinal in Argentina, Grassi read media reports that his former teacher had condemned the country’s legalization of same-sex marriage. So he sent a long e-mail to the cardinal expressing his disappointment as a gay man.

“I stood firm on my position,” Grassi said of what he wrote. “And I ended the e-mail saying: ‘Don’t think it was easy for me to write this e-mail, but I had to do it. And I think it was the right thing to do because 40 years ago you taught me I had to do it.’ ”

The cardinal — who as pope would respond, “Who am I to judge?” when asked about gay priests — responded that his words had been cherry-picked and twisted by the media, according to Grassi, and that the reported sentiment was not true.

“He wrote back to me, telling me, first of all, how sorry he was that he had hurt my feelings, that he had hurt me,” Grassi said. “One of the things he said on that e-mail was that ‘I want you to know that in my work there is absolutely no place for homophobia.’ And I think that’s what I want people to know.”

With that, the alarm for the tenderloin began to beep, and it was back to work.

Michelle Boorstein, Sarah Pulliam Bailey and Carlos Lozada contributed to this report.