The act of fully inserting one's cranium into a women's vagina and ideally crawling into her womb. It is the reverse of the birthing process, specifically crowning. It is advisable to cover one's head in a balloon of some sort in order to maximize pleasure.
Guy: Dude, I want to finger that chick.
Experienced Friend: No man, you gotta try reverse crowning.
- the state of being very close to having to discharge fecal excrement, similiar to the state of "crowning" when giving birth. To reach this state, the turtle must be poking his head out.
"Dude, I'm crowning so bad I think I just baked a hashbrown in my underbritches"
"I have to snap a duece so bad that I'm crowning...can you smell it?"
When the excrement in one's anus cannot be contained any longer and it starts pushing open the sphincter. Probably related to childbirth where the top of the baby's head (the crown) is first visable as it emerges from the vagina.
"OMG I'm crowning so bad it's like I've got a turtle neckhanging from my ass..."