What is the most hilariously passive aggressive thing you've ever done?

When people annoy me sometimes I just ignore them... Or walk away. Usually it's a good way to end with silly arguments that aren't leading anywhere.

Helped someone look for their lost keys at work for an hour, when I had thrown them over the fence into the nearby forest. This was a long time ago, but it felt like the right thing to do at the time.

They did psych testing at work, so I filled out all the questions from the perspective of a psychopath.

Someone I didn't like had just scarfed a party pie whilst getting a coffee. saying "yum!"
I said "Well Mrs Fletchly didn't think so. when she spat it out and left it there."