It's good to pay someone for work they would do.
Crabbe was hired by Draco to paint the house green.
Draco wants to conclude his business with Crabbe.
Draco compliments Crabbe's work on the house and pays him.
Draco's HOA doesn't allow the specific shade of green so Draco doesn't pay Crabbe.
Crabbe is pleased with a paying customer and asks if Draco has more work he needs done.
Draco ends up getting sued by Crabbe for non-payment.