Catholics should not feel they have to breed "like rabbits" because of the Church's ban on contraception, Pope Francis said on Monday, suggesting approved natural family planning methods.
Francis used the unusually frank language during an hour-long news conference on the plane from Manila to Rome at the end of his week-long Asia trip.
The freewheeling encounters have become a hallmark of Francis's simple style, his penchant for straight talk and his ease at using colloquialisms to make his point.
Speaking about corruption, he disclosed that, in his native Argentina in 1994, he almost kicked two government bureaucrats "where the sun doesn't shine" after they tried to involve him in a kickback scheme.
He announced plans to visit Central African Republic and Uganda late this year and a trip to Ecuador, Bolivia and Paraguay during the year.
Francis spoke at length about birth control and population, issues that arose in the Philippines, where the local Church opposes a government law making contraceptives easily available.
"Some think, excuse me if I use the word, that in order to be good Catholics, we have to be like rabbits - but no," he said, adding the Church promoted "responsible parenthood".
He mentioned a woman he recently met who already had seven children by caesarean sections and put her life at risk by becoming pregnant again. He said he chided her for "tempting God" and added: "That was an irresponsibility."
The leader of the 1.2-billion-strong Roman Catholic Church restated its ban on artificial birth control, adding there were "many ways that are allowed" to practise natural family planning.
The Church approves only natural methods of birth control, principally abstinence from sex during a woman's fertile period.
In Sri Lanka and the Philippines, Francis condemned what he called an "ideological colonization" attacking traditional family values in developing countries.
On the plane, he indirectly criticized rich countries and international organizations he said tried to influence lifestyles and morals of young people in poorer nations, comparing their activity to that of 20th century Nazi and Fascist propagandists.
He told of an education minister he once knew who was offered loans to build schools for the poor, but on condition their libraries stocked a book on gender theory, the questioning of traditional male and female roles. He gave no other details.
"This is ideological colonization. They colonize people with ideas that try to change mentalities or structures," he said.
"But this is not new. This was done by the dictatorships of the last century," he said, citing the Hitler Youth and Balilla, its Italian equivalent under Fascist dictator Benito Mussolini.