Karmic Law
All magick is governed by the laws of Karma.  This doesn't mean that spell work can't be fun or enjoyable, only that casting a spell on someone else is a tantamount to casting a spell on yourself.  Karmic law doesn't work on the equal balance; insted, it returns you three times what ever you send out.  Because most of us can't stand a tripple dose  of agravation, I urge you to consider all options carefully before working magick to control or annoy someone else.  With enough planning you could probably find a way to reach your magickal goals without running a manipulative gambit.