Help identifying a fictional character

Slightly different from the usual identification thread, I know. (And my husband’s Andy L, and he can’t identify this one.) A few years ago, I read a novel (don’t remember the title) in which a character made a point of never entering a room with only one exit. Maybe it’s Lord Vetinari in one of the Discworld novels, but if so, can anyone tell me which one?

Any ideas?

Of the books featuring Moist von Lipwig, I’ve only read Going Postal, but it does sound consistent with his character, so maybe in Making Money or Raising Steam.