He made headlines the world over by coming out last year, and then even more by kissing his boyfriend on live TV.

Now Michael Sam, the first openly gay player to be drafted into the NFL, has taken another leap of confidence - and likely controversy - by proposing to his longtime love from what is renowned as one of the holiest Catholic sites.

Sam confirmed his engagement to college sweetheart Vito Cammisano on Twitter on Friday and posted a photo of himself getting on bended knee at St. Peters Basilica - one of the largest church's in the world - in Vatican City.

The move is yet another step the 25-year-old has taken into uncharted territory and is sure to anger church officials and their strict opposition to gay marriage.

The announcement coincided with a visit to the Philippines by Pope Francis, who said in a speech today: 'The family is threatened by growing efforts on the part of some to redefine the very institution of marriage.'

Big question/statement: Micahel Sam, the first openly gay player to be drafted by an NFL team, got down on one knee for boyfriend Vito Cammisano from the top of St. Peter's Basilica in Vatican City

'I said yes': The former Missouri linebacker, who was cut by the Rams and Cowboys this past season, officially announced his engagement to Vito Cammisano (pictured) on Twitter on Friday

Here come the grooms: Michael Sam - who celebrated his 25th birthday in Rome. The pair shared this picture from Italy on Instagram last week

TMZ first announced last week that Sam and Cammisano were engaged after rumors surfaced on social media.

Sam posted the photo of the proposal with the message: 'Thankyou for saying yes.'

Sam is thought to have popped the question on his 25th birthday on January 7.

He and Cammisano were on a European vacation together in Italy, having spent New Years in Spain.

At Christmas, Sam also posted a photo to his Instagram of a ring, where he thanked his boyfriend for 'a great Christmas gift'.

The couple met when Sam was a freshman at the University of Missouri, during one of his first college parties.

It was a lingerie party and Cammisano was dressed as a rabbit, complete with a tail, which Sam told Out magazine he remembered because Cammisano - a star swimmer from 2009 to 2012 - was drunkenly vomiting over a railing from a second-story deck.

'I went up to him to ask if he was OK, and he started cursing at me, screaming, ''F--- off — do you know who I am?'' ' Sam told the mag.

'I told him I didn't care who he was. We didn't speak again for two years.'

Wrong finger: At Christmas Sam posted a photo of a ring his boyfriend had given him, which he appears to be wearing on his right hand in this shot

Nice ring: Sam posted this photo to Instagram at Chrismas, thanking Cammisano for the amazing gift

When Cammisano came out to his swim team in 2011, they started dating, however it was secret, because Sam was closeted.

'Early on, it was awesome,' Sam said during a recent documentary on his life produced by the OWN network.

'And then bad things started to happen.'

'When Vito came to my house, he had to sneak through in and out of the window.

'Vito was getting really tired of that.'

The pair broke up for a few months, until the holidays, when Cammisano realized Sam didn't have anywhere for Christmas.

'So Mickey came to Kansas City for Christmas and that's when (we realized) we missed this,' Cammisano said in the doco.

'It really was Christmas that brought us back together.'

Controversial: Many viewers erupted in anger after a televised kiss was shown on ESPN in May as Sam was drafted by the St. Louis Rams

The pair have been together since, but were not captured in public together until earlier this year.

They hit international headlines in May, when Sam - who had come out in February - made history as the first openly gay NFL draft pick.

The moment he was told he had been drafted by the St. Louis Rams was televised live on ESPN, and an emotional Sam kissed Cammisano in celebration.

The unprecedented moment was met with reactions of joy by most but dismay, anger and even hate by others.

Some online postings deplored the kiss as inappropriate for family viewing.

Sam and Cammisano shared another public kiss last month when Sam accepted a GQ Man of the Year award.

Sealed with a kiss: NFL player Michael Sam kisses his boyfriend Vito Cammisano after being named GQ Man of the Year 2014 in West Hollywood last month

Happy couple: Sam was nominated for the award along with Chris Pratt, Steve Carell, Dave Chappelle, Ansel Elgort and Shailene Woodley and featured on a joint cover of GQ magazine in December

Sam recently told Oprah Winfrey that while the aftermath of the moment was surprising, he would do it again.

'Absolutely. I came out so I wouldn't have to hide myself,' he said in the interview.

'That was me. What you saw was me. It wasn't staged. I was very emotional.

'And when I got that phone call it was one of the happiest moments of my life.

'It was three long days, coming close to the end of that, almost not being drafted.

'I wanted to share a moment with the one who had spent the same three days, I wanted to share a moment with him.

'I'm not a pretender anymore.'

Sam was cut from the St. Louis Rams and then, in October, was dropped by the Dallas Cowboys.