If you follow American popular news (and, unless you like sticking sharp glass in your eyes, that's probably a big if), you've likely heard about the now disgraced comedian's practice of masturbating in front of women. The interesting part, and the part he highlighted himself in his mea culpa is that he never did it "without asking first."
Such behavior obviously points toward an exhibitionist streak. But there is also an aspect of desire at play; it seems that part of his sexual gratification was the woman's expressed desire to see him a) become an object of sexual attention, and b) in such a vulnerable position.
It reminds me of when, as a boy, my pediatrician used to exam my genitals. In the days leading up to the exam I was always filled with complete dread. I was embarrassed. I had a childlike preoccupation with what she might think about me when she saw my penis. I was unable to see the situation for what it was: a grown woman doing her job, likely with no thought or concern for the little boy's penis in front of her other than, 'is it healthy?' This form of distortion seems implicit in Louis's deviant behavior. Because in reality there are very few women who want to see a strange man masturbate in front of them. Male masturbation is not the most graceful act. And Louis is, to put it mildly, not a very handsome man. But he still wanted to have that experience of being treated as a sexual object -- to be desired, even if on the most base level. What does this say about his sense of self worth?
The second aspect, that of vulnerability, is also worth exploring. To reveal an intimate aspect of yourself to the external world has even more currency in the age of anonymity. Although one must wonder in C.K's case if such repeated behavior eventually lost its dye of intimacy and became stained with degeneracy.