Noun: A sexual act where the male anally penetrates the female and then, "reaches around" and inserts his fingers into her vagina. If all 4 fingers are used the motion is similar to a cowboy tugging on his belt buckle.
When facing adversity, some individuals rise up to meet the challenge. This antonym of a more well known phrase describes much the opposite—a person who cannot handle pressure and crumples (buckles) in the face of hardship, frequently leading to their own failure.
"I would say 'when the going get tough, the tough get going', but even though she studied for weeks, when Anna went in for the final test, she totally blew it."
"I'm not surprised, it's Anna after all. When the going gets tough, she buckles like a belt."
("When the going gets tough they buckle like a belt used" when in a sentence may include pronounces, or a name instead.)
Shoving the your balls above the top of your pants while keeping your penis below, exposing only the scrotum, preferably to distract an opponent or incite ridicule at the sake of his questionable sexuality.
I was playing beer pong and steve gave me the Tijuana belt buckle.