How does Gregor's father change after Gregor's transformation?

Gregor's father, having lived a "laborious though unsuccessful life" and collapsed his business, has become exceptionally lazy, doing nothing while his son earns all the money. When misfortune strikes, Mr. Samsa puts on a uniform and goes to work. He is suspicious of the transformed Gregor from the beginning, and always assumes the worst if his son emerges from his room. He first wounds Gregor while trying to shove him into his room and then cripples him by throwing an apple into his back.