This is an excellent point. I always assumed the emotional aspect of sex was part of the reason the verb "withholding" was used, much in the same way it's used

This is an excellent point. I always assumed the emotional aspect of sex was part of the reason the verb "withholding" was used, much in the same way it's used to describe a more generalized "withholding" of love and affection, whether it's as simple as a kind word or hug on upwards to the more carnal. But withholding something implies that thing is deserved or earned, which runs contrary to body autonomy. Even though he used this language, I thought the author did a pretty good job explaining why sex isn't something that's rarely "withheld" as a means to an end. But our language around love (physical and emotional) and relationships needs work.