Professor Proton: Rule number one in a marriage: don't go to bed angry.
Sheldon: That makes sense.
Professor Proton: Rule number two in a marriage: if you don't recognize the shoes under your bed, they're not your shoes.
Sheldon: Because they're her shoes?
Professor Proton: (sighs) N-Never mind, just-just go with rule number one.
Sheldon: Thank you, Arthur.
Professor Proton: Uh, before you go, can I ask you a question?
Sheldon: Of course.
Professor Proton: Does this look lean to you? I ordered lean.