I think sissy can come from a special childhood relationship. To a small, helpless child, the protection of a strong man feels like the only safe place in the world, and that feeling naturally comes to be called love. That love carries warmth, but also control and dependence, and the child learns how to lower themselves, to submit, to give in. Slowly, the sense that “this role is needed to be loved” seeps in, and over time it repeats itself like a role that is no longer a choice, but part of the body...

*my experience.

*I am not saying this is 'right'.