She sticks her pussy lips over you and slowly but surely starts the unbirth process. You only hope you'll find some way for having air in there, otherwise you'll pass out. She is so wet and slick that before you can even contemplate this she is up to your shoulders.

"You're going to have to get up pretty soon, gravity will take over" she says as she gets to your waist. You stand and she finishes up. He womb is extended enough that she looks pregnant from the outside. She giggles as your squirm around. What happens next?