Payback's a bitch American spoken language informal
Don't rush to celebrate, payback's a bitch.
Don't do something bad to someone and think you will benefit from it. Payback's a bitch.
If someone has a cast iron stomach, they have a strong stomach that can digest unusual food and even bad food without being ill.
Jimmy must have a cast-iron stomach, when he drank milk with lime juice and felt perfectly fine afterward.