Drink up
Sometimes being passive-aggressive works – people get the message, and it speaks louder than shouting or yelling or expressing emotions – since some people react better to humor. Other times, people take it too literally and the joke is on you. I’m not sure who’s being more passive-aggressive here, I want to say it’s Dave – but which one?
Clearly, this person was trying to say the beverage belongs exclusively to Dave (yet another creative sign to keep away office food thieves), but he didn’t consider that there might be another Dave in the office. That’s why knowing all your peers is important – not for social gatherings and friendship, but to make sure your passive-aggressiveness works as intended.