I have not written a hub on casting a spell on someone else... would highly suggest deterring anyone from doing such a thing. But have written a couple of spell hubs from charging candles to cast spells and casting a career spell. Casting a spell on another person could have a 10 fold negative impact on you.
I get the humor of this question... I would try to become more attentive to their stories, and try to become more interesting myself. Erotic notions are usually developed by the most mundane aspects.