What is the most evil thing you have done to an ex.?

I have been told payback is a ***** and i am looking for the ulitimate payback. If you are going to call me nasty and vindictive then dont bother replying. I was thinking as he was biual (and never told me) maybe his phone no. on the wall of the mens toilets or his profile (with pic) on the supermarket for sale board. Any ideas out there from other women that have been crossed.