CBT fantasy, in the context of BDSM, stands for Cock and Ball Torture fantasy. It involves scenarios, role-playing, or mental imagery where one or more individuals derive sexual arousal from the idea of inflicting or receiving pain, discomfort, or humiliation specifically focused on the male genitalia, namely the penis and testicles.

In CBT fantasy, participants may imagine scenarios where various forms of stimulation, restraint, impact, or manipulation are applied to the genitals for the purposes of sexual pleasure or arousal. This can include activities such as genital bondage, squeezing, slapping, pinching, stretching, clamping, whipping, or even more intense forms of sensation play.