Complex sentence: One day, while the boyfriend is watching TV, the girlfriend's body comes back to life and chases him out of the house, in fear, he runs into her graveyard, where the girlfriend pierces his heart out and he falls to the ground lifeless.
Split into simpler sentences: One day, while the boyfriend is watching TV, the girlfriend's body comes back to life and chases him out of the house. In fear, he runs into her graveyard, where the girlfriend pierces his heart out and he falls to the ground lifeless.