It works.  I mean if she has a hold on him like that it can make it even more fun for him to screw with her.  She can bind him but then something breaks the circle and he disappears.  She might think the binding did not work and he is the only one that knows?  So he looks her up to get close to her to try and find a way to break the binding before she finds out it worked?  I don't know but these are a few ideas.  What u think?