Pre or post sex act where you stick your half-erect cock in a mayo jar and slap it in a woman's ear while singing "The Final Countdown." Typically reserved for counting down the final 10 seconds on New Year's eve, but it can be used to count down other special occasions.
"What did you do for New Year's Eve?"
"Me and the old lady brought in the New Year with Reverse Cowgirl, followed by the ol' New Year's Gong, in-time with Dick Clark's countdown."
"I used Olive Oil mayo on my last New Year's Gong, and now my girlfriend's ear smells like an Italian rubbed his nutsack on her face."