This television episode refers to:
Jan meets with Michael on Valentine's Day while he's in NYC, to discuss a problem. Jan is worried that they will both be fired, because the CFO of Dunder Mifflin thinks she and Michael slept together. Michael explains that technically, they fell asleep in the same bed. He tells Jan that he will fix things and talk to David, the CFO. Jan says "Surely, you cannot be serious?" Michael replies " I am serious. And don't call me Shirley. Airplane."