This one is really interesting; espically given the multiple ways it can be interpreted. Even so obvious an act, as this nipple twist, can be filtered through so many different reality filters, so many different lens of symbolic interepretation and meaning that one could ask for summaries of the symbolism and end up with a dozen different answers. It's literally a great example, and intellectual exploration, of the idea that even when things are literally black and white, they can be more than black and white.
(For example, Black can mean evil. Or it can indicate the hidden subconscious part of the mind. Or it could indicate how the impulses of lust are not understood on an intellectual level- and thus the conscious mind is "in the dark" as to how to understand it as an idea other than an expirence. Basically a great use of how different ideas being used by the same symbol/name can lead to a great deal of confusion when opposite ideas use the same expression.)
That and he's rolling it like a bullet.