Is all fornication a mortal sin?

Given two people (one of each sex) who are both well past the age of conception, does their fornication (they are not married to anyone, both being widowed) constitute a sin, mortal or venial?

Dear friend,

The act of sexual intercourse is the physical expression of vows of marital commitment made at the altar. It is a holy thing. Such behavior outside of the context of those vows is a lie in that it represents nothing more the desire for the pleasure of the moment with another to whom one is not married. It is a mortal sin–regardless of how old the individuals may be.

Yes fornication, of itself, is always a mortal sin.

Fr. Vincent Serpa, O.P.

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