Pokemon Vore Adventure - Page 301 - you manage to get the Charmander out before losing consciousness inside the Buizel's tailhole. - By Pachirisu_And_Asmodeus - Overview
Once you lose consciousness, you slip back into the Buizel's stomach as the Buizel gets on top of the unconscious Charmander and begins licking her tailhole while her acids arrive in her stomach to digest you.
