When I saw this, the main question I asked myself was:- 'Why is this in Covens?'' Nevertheless, Love spells, as Flagg said, can backfire terribly. They are a form of black magick and karma can come back to get you.
So be careful when you are doing a love spell. Also, if they are under a spell, is that really loving? Wouldnt you rather they just love you without being under a spell?
If you love someone, set them free. If it was meant to be, they'll come back.