Setup: Michael & Holly are on a ferris wheel at Toby's goodbye party. Holly is telling Michael about her previous employer.

Holly: "It was easy to get in but impossible to rise up."

Michael: (trailing off) TWSS.

From: Goodbye Toby (Season 4, Episode 14)

Setup: Jan is suing Dunder Mifflin for wrongful termination and Michael is being questioned about the company's treatment of her. A lawyer is asking Michael to clarify their relationship.

Lawyer: "And you were directly under her the entire time?"
Michael: TWSS.
...
Michael: "Come again."
Michael: TWSS.

From: The Deposition (Season 4, Episode 8)

Setup: At the dinner party, Michael & Jan ar talking about Jan's candle business.

Michael: Oh, good, then I'll be your first customer.
Jan: "You're hardly my first."
Michael: TWSS.

From: Dinner Party (Season 4, Episode 9)

Setup: Dwight asks Angela if she wants some of his beet salad.

Angela: "The thought of popping one of your beets into my mouth makes me want to vomit."
(Missed): TWSS.

From: Dinner Party (Season 4, Episode 9)