"Me being gay is no different [to the pope] than me having blue eyes," Grassi told ABC News today. "It's not different than me living in Washington. It is part of my life. And the way he accepted my boyfriend, it is a validation of how happy he is that two people of the same sex can be together and happy and miss each other when we are not close to each other."
Grassi brought his boyfriend of 19 years, Iwan Bagus, to the private meeting with Francis at the Papal Nunciature in Washington, D.C., on September 23.
"When he [Francis] shows up on that corridor and I see him, and we embrace, it was so wonderful," Grassi said of the meeting.
"I joked with him, we told each other a couple of jokes, and then I introduced all my friends to him, and they had things to bless and we talked," Grassi said. "He asked me how my business is doing, what kind of food I was cooking, really things of a friend, that a friend would ask another friend.
"We never discussed anything about me or my boyfriend," Grassi said. "We discussed my life, we talked about a lot of other things. I didn't feel it was important to him to discuss it with me. He didn't bring it up. I didn't bring it up.
"I think the message that he puts forth is that of understanding, is that of not judging," he said.
Grassi first met Francis when the future pope was his teacher.
"I think that we all had one teacher, one mentor that we love very much and we consider that person extraordinary, remarkable. I think that he was he has a superior mind, he has an intelligence that goes beyond the common intelligence of regular people," Grassi said.
When Grassi learned the pope was coming to the U.S., he wrote to him.
"I said, 'I know you're going to be very busy but I would love to see you, and if you have time, and if you think that it would be possible, let me know.' And he wrote back to me and said, 'Let me think of a time and schedule that will work for both of us.' Something like that, something to that effect," Grassi said.
"Then when I realized how busy and exhausting his schedule was here in the states. ... I thought, its better if I don't see him this time. We can always see each other sometime else."
But two weeks before Francis' trip, Grassi received a surprising call.
"He called my cell phone. And I just couldn't believe it," Grassi said. "I thought it was a prank at the beginning. But he called me by the nickname when I was a student so I knew it was him. ... I said 'Oh my God what are you doing.' And he said, 'Well I have your phone number you told me to call you.' And I said, 'Yeah, but call me from Washington ... you don't have to pay long distance!'
"He's just so much fun. And he said, 'Well, I would like to give you a hug when I'm in Washington.' And I thought, 'Well OK, are you sure that you have the time?' And he said 'Yeah, I have the time. I want to make time.'"
Fr. Federico Lombardi, the Director of Holy See Press Office, confirmed Grassi's meeting with the pope in a statement Friday.
"Mr. Yayo Grassi, a former Argentine student of Pope Francis, who had already met other times in the past with the Pope, asked to present his mother and several friends to the Pope during the Pope's stay in Washington, D.C.," the statement said. "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 pope's U.S. trip also included a meeting with Kim Davis, the Kentucky clerk who has refused to marry same-sex couples.