Master/slave (BDSM)
In BDSM, Master/slave, M/s or sexual slavery is a relationship in which one individual serves another in a consensual authority-exchange structured relationship
Bondage (BDSM)
Bondage in the BDSM subculture, is the practice of consensually tying, binding, or restraining a partner for erotic, aesthetic, or somatosensory stimulation.