during fellatio: the member giving head waits for the receiver to approach orgasm, gently tugs downward on the hairs at the base of the scrotum, and with the other hand, violently punches his or her partner in the grundle.

During a well-timed, professional Turkey Tickle, the impact of the taint hit will occur simultaneously with ejaculation.

When you're being horny (especially around friends) and as a result shame ensues.