Unbirthing

The Japanese Government spends over ¥1bn (or about $9.8 million) a year to research and develop new forms of sexual depravity.

Retarded fantasy which is sadly not exclusive to the furry "lifestyle", in which one participant crawls into the vagina of the other, and makes base camp in the uterus. Fucking hot. Some argue that Nirvana started this fetish in the song Heart-shaped Box:

Throw down your umbilical noose so I can climb right back

Unbirthing is sometimes classified as a subcategory of voraphilia, in which people are ingested by various methods (not least of which is the good old minge). May or may not involve vagina dentata or other such depravity, because hey, as long as we're pulling fetishes out of fucking nowhere, let's go wild!

Unbirthing is not to be confused with rebirthing, which is a new-age pop parenting technique favored by fugly adoptive parents who are too chromosomally deficient to breed traditionally. The technique is designed to try and force adopted children to love the hideous ham beasts that stole them from their original parents by enlisting the aid of professional child therapists who teach the victims how to suffocate to death via pillow and blanket smothering whilst having their heads forcibly squeezed between the thunder thighs of a frumpy fatass who desperately wants to be loved.