The implication of this text is that husbands and wives should satisfy each other sexually, so that their eyes and hearts do not roam after satisfaction elsewhere. There are many elements that make up this satisfaction. Let me mention three. One Paul mentions in verse 5, namely, the frequency of sexual intercourse. He says that married couples should not abstain very long from sexual relations lest they fall prey to the temptation of adultery.
Frequency is one element that makes up the satisfaction of sexual relations.
Another would be whether a husband and wife are physically attractive to each other. I admit that this is a very sensitive and very complex area. It is sensitive because there are many things about ourselves that we can't change and others that are hard to change. It is complex because the inner union of two people can cause them to see beauty in each other that others can't see. Nevertheless, if it is true that being physically attractive to each other is part of what makes sexual relations satisfying, then I think this text implies that husbands and wives have a spiritual duty to try to be attractive to each other.