“What’s the deal with sadomasochistic relationships?” — answering the question.
The sadomasochistic dynamic is an anesthesia for traumas sustained during a period of high psychological vulnerability. They require extreme compensatory measures because they have penetrated deeply into the personality structure.
The sadist and the masochist are the same person on the same spectrum, which is why they easily switch from the role of the aggressor to the role of the victim.
To use the sadomasochistic method as anesthesia — when it acts as a form of therapy rather than just an experiment — empathy is required: the ability to resonate with another person, to feel how much they are hurting, suffering, or afraid.
Most sadists grew up in environments of severe abuse by their parents. For them, pain and total control are the only understandable feedback from the outside world: at least some form of attention, confirmation of their existence, and a format of intimacy. Experiencing deep self-hatred toward their past vulnerable self, the aggressor identifies with the victim. By inflicting pain, they attempt in the moment — through "observing themselves from the outside" — to overcome internal helplessness, shame, and fear.
They temporarily release tension and immediately seek punishment to drown out guilt through suffering. Being an aggressor is a massive stress that requires total control. Switching to the role of the victim removes responsibility and brings an immense psychological release.
It is a vicious circle: since the actual internal conflict (self-hatred) is not resolved through violence against another, the shame and guilt only intensify after the act of aggression, demanding new, more sophisticated forms of compensation.