"Promiscuity often expresses a need for constant love and attention from others, in order to hold on to positive feelings about oneself. The borderline typically lacks consistent positive self-regard and requires continuous reassurance. A borderline woman, lacking in self-esteem, may perceive her physical attractiveness as her only asset and may require confirmation of her worth by engaging in frequent sexual encounters. Such involvements avoid the pain of being alone and provide artificial relationships she can totally control. Feeling desired can instill a sense of identity. When self-punishment becomes a prominent part of the psycho dynamics, humiliation and masochistic perversions may enter the relationships. From this perspective, it is logical to speculate that many prostitutes and pornographic actors and models may be borderline."
from the book “I Hate You - don’t leave me: Understanding the Borderline Personality” by Jerold J. Kreisman, M.D., & Hal Straus