hibernating squirrel
We know squirrels hibernate, and they dig in the dirt to hide their nuts... So... The Hibernating Squirrel is when you are doing a chick doggy style in the ass(Digging in the Dirt) and you tuck your balls inside her vagina (Hide your nuts)
"yo dude did you bang that broad last night?"
"Yeah man, I gave her the ol' Hibernating Squirrel!"
"Yeah man, I gave her the ol' Hibernating Squirrel!"