This is just my guess, I haven't read anything beyond this latest manga chapter:
Ah, yes, fuck the girls until they become addicted to his dick, that way they become uninterested and uninterested in the King's dick, becoming dissatisfied with the sex from the King and ultimately cause the King to spiral out of control in his fear of losing control over everyone, which then causes him to actually lose control over the strongest subjects, opening up a perfect window of opportunity to take him down, once and for all.