Workplace outing

Recently I overheard this piece of office humour:

Colleague A: "We need a workplace outing."
Colleague B: "OK - your magazine's gay!"

(For those who don't get the joke - 'outing' can mean either "an excursion" or "the disclosure of the undeclared homosexuality" (both OED). I'm not sure whether the former meaning is widely used outside British English...)