I Corinthians 7:2, 28, 36, 39

Nevertheless, because of sexual immorality, let each man have his own wife, and let each woman have her own husband.

But even if you do marry, you have not sinned; and if a virgin marries, she has not sinned. Nevertheless such will have trouble in the flesh, but I would spare you.

But if any man thinks he is behaving improperly toward his virgin, if she is past the flower of youth, and thus it must be, let him do what he wishes. He does not sin; let them marry.

A wife is bound by law as long as her husband lives; but if her husband dies, she is at liberty to be married to whom she wishes, only in the Lord.