1 Corinthians 7:5
5 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.
The NKJV and the NIV translate the word Defraud incorrectly.
“That no one should take advantage of and defraud his brother in this matter.” NKJV.
“That in this matter, no one should wrong or take advantage of a brother or sister.” NIV.
The Greek word Defraud is ἀφυστερέω apostereo, which means to keep something back by fraud. The English word fraud means to illegally obtain money from someone by deception.
It doesn’t mean to take advantage. There is another Greek word Paul could have used for “take advantage,” and it is not the word he uses here.
The NKJV and NIV add the word brother, or brother or sister. Neither brother or sister is in the Greek text.
The context is not about defrauding a brother or sister, it is clearly about marriage and sexual relations between a husband and wife. The husband and wife are not to deceive each other from due benevolence (vs. 3). To do so is to defraud the other of what God has given to the marriage.
There is an agreement that takes place in a healthy marriage, where each consent for a time to forego sexual relations. The reason for the cessation of sexual relations for a time is so the husband and wife may, through fasting and prayer, become strengthened in their spiritual walk with the Lord.
This is the way humans are made; with a need for a sexual outlet. But they need to come together so that Satan tempt you not for your incontinency. Incontinence means a lack of self-control. Husbands and wives need a sexual outlet and they are not to defraud each other of it. This takes us back to verse 2, every man is to have his own wife and let every woman have her own husband.