It's true. A relationship only works when both people are happy and satisfied. If a guy has sex denied to him, and he can't do any better or get it anywhere else, then he'll tolerate it. If he can have sex somewhere else, he either does or he leaves.
So sexual control only works on guys of lesser value. But that's why women always say things like "I don't ever think I can date a man who is better looking than me" and settle for less attractive men who they know won't cheat on them because few other women find them desirable.