Forty "I do's" — or "Si" in Italian — have been pronounced in St. Peter's Basilica as Pope Francis married 20 couples, with one bride already a mother.

Francis in his homily Sunday likened families to the "bricks that build society."

Among the couples, all from the Rome area, was one in which the groom's first marriage was annulled by the church and the bride has a daughter she had while an unmarried woman in an earlier relationship.

The Vatican views sex outside marriage as a sin, but Francis stresses the church should be a forgiving one.

Francis said marriage was "real life, not some TV show." He told couples to expect conflicts but that Jesus' love would help them when love runs out. Church teaching opposes divorce.