Snape: "Hey, Potter. What's up with Lupin?"

James: "You mean the man who disappears every full moon?"

James: "The man whose first name has to do with wolves?"

James: "The man whose last name means 'Moon?'"

James: "The man whose fathers name means 'Wolf?'"

James: "The man whose Patronus is a wolf?"

Snape: "Yeah".

James: "No clue".