Since when did revenge have to include something as trivial as proving someone wrong? Perhaps my revenge will be that you lose the ability to cum ever again. ![Evil >:D](http://www.intensitysquared.com/Smileys/default/evil.gif)
That might be a favor.
Remember, you're dealing with
a complex thing here. I doubt that
you could come up with something
which would be clearly BAD for me.