Cock and ball torture (CBT) is a sexual activity involving application of pain or constriction to the male genitals.

This may involve directly painful activities, such as:

• Genital piercing
• Wax play
• Genital spanking
• Squeezing
• Ball-busting
• Genital flogging
• Urethral play
• Tickle torture
• Erotic electrostimulation
• Or even kicking

The recipient of such activities may receive direct physical pleasure via masochism, or knowledge that the play is pleasing to a sadistic dominant. WIKIPEDIA