Published: 2018-01-22 21:40:28 BdST
"Someone told me I was crazy to do something like that," he joked during a news conference on the plane taking him back to Rome from Lima, were he ended a trip to Chile and Peru.
In the first such ceremony on a papal flight, Francis married Paula Podest Ruiz, 39, and Carlos Ciuffardi Elorriga, 41, both cabin attendants on Latam airlines.
While the gesture made world headlines and was mostly well-received by Catholics, conservative Catholic commentators and bloggers who regularly criticise the pope on a host of issues blasted the wedding at 36,000 feet.
They said it would make it difficult for pastors to deal with Catholic couples who want to get married in unusual secular locations instead of a church. Those couples would say "the pope did it, why can't you?" one commentator wrote.
But the pope said the situation of the Chilean couple was a particular one because they had been already been married in a civil service eight years ago and were not able to marry in their parish church because it collapsed in a 2010 earthquake.
"I questioned them (about marriage) and the responses were clear ... it was clear they had made a commitment for life," the pope said, adding that the couple had even remembered subjects from the Catholic pre-marriage courses they had taken long ago.
"Tell the pastors that they were prepared and I made a judgement call. The sacraments are for people. All the conditions were clear," he said.