a) the act of specifically raping a virgin teen girl in the anus

b) arriving somewhere unexpectedly, when they least expect you.
sociologist of criminal behavior, (visiting the cemetery of Marion State Prison, Illinois): Ghost Poinsalet, I hear you are famous, even among ghosts, in this cemetery. What have you been incarcerated, and executed for, 27 years ago?

ghost of Matthew Poinsalet (character from Dead Man Walking): Sir, it was for knocking at your back door, definition b), to the house of 2 virgin teen girls, then committing knocking at your back door, definition a), and then finally murdering my victims.

sociologist (under his breath): How atrocious, may we condemn all child rapists and murderers to the electric chair, Amen.
by Sexydimma June 1, 2015
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Drunk, horny hot air balloonists reviewing a poor weather forecast the evening prior to a flight and lubing up for a daisy chain group fuck as a consolation to an early morning balloon flight.
The radar tomorrow looks like shit. Stop at the Walmart and grab their best bottle of silicon lube, looks like the best we’re gonna get out of this weekend is a moist back door cold front.
by Finish Line October 5, 2022
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"Oi! Is it true that your mum got her back doors kicked in last week?"
"Yes, Vicar, it's true."
by Sir Aethelred Pisp August 22, 2021
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A person or person's who stands guard of there back door but secretly wants to find a good fitting key.
it seemed it was a case of a 'back door gate keeper' when questioned about there sexual preferance
by Major Rummy January 15, 2010
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When you connect enough restaurant straws to boof yourself!
When Frank couldn’t find anyone boof him at after hours, he had to resort to the back door Mercado to get the job done.
by TrashmanB September 4, 2023
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When someone is having a gaming session whilst simultaneously doing someone from behind.
Bro tonight my girlfriend and I are going to try back door gaming
by AtticusFinchTheSecond January 6, 2023
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