Yeah, I didn't mean to imply that it would prevent them from feeding so much as it would make it much more difficult for the demon to manipulate them.

Each demon isn't predisposed to a particular emotion. The Houses are, and they subtly push their scions down their chosen road, but WoJ is that any White Court can learn to feed on any emotion if they work at it hard enough (example from the case files: Madrigal Raith). The reason that Lust, Fear, and Despair are the most successful is because White Court Vampires are changed by their diet. Vampires that feed on Lust, Fear, or Despair (or some mix thereof) become potent predators capable of thriving in the cutthroat supernatural community. Ostensibly, a splinter group could try to found a new house based on feeding upon the warm snuggliness of drinking hot cocoa on a cold winter's morning, but their scions wouldn't have the sheer ruthlessness to survive the long term.

One might presume, then, that a Raith deprived of their sex drive would simply take to feeding on a different emotion. (This might be a cool opportunity to throw in a unique one-off vampire that feeds on, say, Envy, to reflect their post-balls relationship with House Raith.)