The Apostle Paul gives instruction in I Corinthians 7 about sex in marriage, and points out that it is Necessary, Blessed, and God-Glorifying. This is a very realistic approach to sex and marriage. Realism is that we acknowledge the strong desire created in man and woman by God, a lesson the child of God forgets to his harm. All by itself, this overthrows the teaching that sex in marriage is only for producing children. Paul means that it is better to marry than to burn in one's lusts .
Marriage is the remedy for that.
Christian husbands and Christian wives owe it to their spouse to give themselves to each other physically. Because this is Jesus' command, you owe it to Jesus to give yourself to your spouse. In the next verse, Paul explains how this can be called a debt. The Christian viewpoint in everything is different. This is the teaching of I Corinthians 7 in verse 5.