Since outside the Church there is no salvation, there is no known salvation to contradict the norm for salvation which is faith and baptism(Ad Gentes 7), inter faith marriages are a mortal sin. They are adultery.

 Since outside the Church there is no salvation, there is no known salvation to contradict the norm for salvation which is faith and baptism(Ad Gentes 7), inter faith marriages are a mortal sin. They are adultery. The non Catholic spouse is outside the Church and the Catholic spouse is living in adultery and fornication and so will go to Hell. -Lionel Andrades