When you ram your rod into the fertile sod of a broad, specifically in her butthole and you withdrawal faster than the french at a war meeting her butthole will resemble a birdhouse's hole. You stare magnificently at what you have created, spit in or around it and then take a photo.
I was talking on the phone with my homie Z-Man and he was telling me about this dude that birdholed this girl and her butthole wouldn't close.
If engaging in an anal invasion, a woman's ass elasticity will manifest itself as the ubiquitous birdhole.
An old man who fought the Japs in WWII and sends you $100 dollar checks which signify the approximate amount of love directed at you. Carries the name "Grandpants" due to the high position of the Sears Docker Elastic pants he wears above his hip bones. He also loves Spaghetti and Meatballs at Dinos, hates awkwardness and negroes. Favorite phrase is "Ehh your a good kid Brendan, I live next store to the niggers."