1 Corinthians 7:3,4 - The husband should fulfil his marital duty to his wife

7:3

So “the husband should fulfil his marital duty to his wife and likewise the wife to her husband”. In the culture of the time the expectations were that the wife should remain faithful, but it was normal for the man to go outside the marriage for sexual pleasure as well, whether that be with other women, other men, prostitutes or boys. One of the reasons that the gospel proved to be appealing to many women was that it taught that the husband and the wife should act with equal self-control and fidelity.

7:4

We don't appreciate how radical Paul’s teaching in this verse was. Paul says that neither the husband nor the wife have authority over their own bodies. Instead both yield their bodies to the other partner. By the way, this does not mean that the other partner should not exercise respect and care for their partner’s body. Paul is teaching that sex within marriage is a matter of mutual giving.