May as well add one more: imagine a computer controlled device that effectively turned on the pleasure centers of the brain on command. This device would be used on someone to condition them to associate pleasure with something they ordinarily would never pursue, and then they would continue seeking out the same stimulus to get that same rush. Over time, the association would become natural and (mostly) permanent, the pleasure of that stimulus a response that now requires no outside prompting.
In a story I read, for example (obviously, all of this is immoral in reality, but we're in fantasy-land now), this sort of technology was used on a jogger in the park walking her Great Dane, which made her want him sexually. With repeated encounters, she was essentially made to want this for herself, and ultimately was turned on every time she saw a well-endowed male dog from then on.