Cock and ball torture (CBT) is a sexual activity involving the consensual application of pain, pressure, or constriction to the male genitals. Practices can include squeezing, genital spanking, genital piercing, wax play, urethral play, erotic electrostimulation, and impact play such as ballbusting. The testicles are particularly sensitive to pain, and even relatively minor impact can cause pain or discomfort.