Complex sentence: Pooh thanks Rabbit and eats leftover honey on his stomach, before trying to go out the front door which he came in through, but becomes stuck because of his now over-sized botton, which has become too fat to fit through the door.
Split into simpler sentences: Pooh thanks Rabbit and eats leftover honey on his stomach, which is full and much rounder. He tries to go out the front door which he came in through, but becomes stuck because of his now over-sized body, which has become too fat to fit through the door.