Is sex okay for a Catholic couple in a civil marriage, while waiting for a Church wedding?

My friend (U.S. citizen) and his Columbian fiancée recently got married civilly for citizenship purposes. They were living at his parent’s house in separate rooms and planned to do so until their Catholic wedding in January 2014. He bought a house but they didn’t plan to move in together until after the Catholic wedding. However, the Catholic priest that is preparing them told them it’s ok to live together in their new house now (September 2013). He gave them his blessing and said it would be good for them to away from his parents!

I’m confused. If they have sex now, is it considered a mortal sin by the Catholic church?
Should I recognize their marriage since the priest apparently did?
Is their civil marriage ok in God’s eyes?

Dear friend,

The Church does not consider them to be validly married. Living apart is quite appropriate. The priest had no right to encourage them to live together where they could easily be tempted to sin. His advice goes completely against Church teaching. I hope they have enough sense to recognize how inappropriate his advice is. Please show them this. They AND the especially the priest are in my prayers.

Fr. Vincent Serpa, O.P.

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