Stuff it in a box, put it in a box somewhere you can forgot about for a few years until your head clears. Then look at it and decide if it's worth keeping.
Best 'payback' I ever got during a breakup took 4 years to play itself out. My 'GF' at the time was being a royal pain, and couldn't decide if she wanted me, or her ex BF, and kept bouncing back and forth (chick was hot, so she was worth the anguish).
I helped set up her new waterbed one night, and knowing I about ready to hit the road for good, I decided to have a little fun. I took a big magic marker and wrote ''Spike' was here, and helped break it in' on the bottom panel of the waterbed. Then signed it with a date 3 years later. Dumped her a few months later and forgot about it.
Ran into her 5 years later, after she was married for a year. She had settled down quite a bit and was happy, but she insisted on telling me her new husband found the message after they bought a house and moved the waterbed, and she had a helluva time explaining the message under the bed.
I need to sell that one to a Hollywood screenwriter.