What does it mean to defraud your spouse in 1 Corinthians 7:5?
In 1 Corinthians 7:5, to defraud a spouse means withholding the marriage bed or sexual satisfaction to gain an advantage. Paul presents marriage as a 50-50 union where husband and wife each owe the other sexual needs, so deprivation is wrong except by mutual consent.
Les explains that 1 Corinthians 7 addresses the husband-wife relationship as a 50-50 union. Verse 4 says the wife does not have power over her own body, and likewise the husband does not have power over his own body. Paul is talking about satisfying the sexual needs of both parties. In verse 5, because it is a 50-50 situation, the husband must be aware of the wife's needs and the wife of the husband's needs, so they are not to defraud one another except by consent. Les relates this to the warning never to use sex as a lever against your spouse, meaning wives should not withhold the marriage bed to gain an advantage, and vice versa.
Defraud ye not one the other, except it be with consent for a time, that ye may give yourselves to fasting and prayer; and come together again, that Satan tempt you not for your incontinency.