Due Benevolence
What do you do as a Christian man, when you're not sexually satisfied with your wife?
Paul makes very clear that the married couple has an obligation to each other sexually (marital duty, debt). To refuse to meet one’s spouse’s sexual desires is to deprive (rob, as in 6:8) the spouse of what is their right
The wife’s body does not belong to her alone but also to her husband (v. 4) is literally “the wife does not have authority [power, right] over her own body, but yields it to her husband” (TNIV). The idea is that the wife (or husband) does not have the freedom to do as she (or he) pleases with her (or his) own body in this matter, because the other has a rightful claim to sexual satisfaction. This requires mutual submission (Eph 5:21).
21 And out of your reverence for Christ be supportive of each other in love.
28 Husbands have the obligation of loving and caring for their wives the same way they love and care for their own bodies, for to love your wife is to love your own self.
29 No one abuses his own body, but pampers it—serving and satisfying its needs. That’s exactly what Christ does for his church! 30 He serves and satisfies usf as members of his body.
31 For this reason a man is to leave his father and his mother and lovingly hold to his wife, since the two have become joined as one flesh
