Why does Walter White never pay for pizza? It's always on the house.

What does Mike Tyson, after he's finished baking, have in common with Walter White? A methy kitchen.

Walter White decided to buy a pizza for his son Walter: Hey son I bought you a pizza so you can share it with your friends. Flynn: Thanks dad, how much do I owe you? Walter: It's on the house.

Why did Walter White not pay for his pizza? Because it was on the house.