Satyriasis
This is a vampiric version of Nymphomania, in which the sufferer remains sexually obsessed with mortals.
A notable few vampries have subconsciously denied their undead state, and find themselves "sexually" attracted to mortals, other vampires (and, in particularly severe cases, other paramours). Of course, as vampires lack the ability to procreate due to their undead status, any couplings they may achieve are inevitably frustrating and fruitless.
Such limitations do not hinder the efforts of those who suffer from this derangement, however, and they pursue the carnal act with every ounce of their being. By spending blood, the vampire may "function" and even bring a partner to climax, provided they're not dead, too. Vampires under the influence of this derangement often sink into ever more depraved activity, hoping to somehow stimulate the pleasures they have been denied. Indeed, outside of "normal" hetero- and homosexual affairs, these vampires may indulge in bestiality, pedophilia, rape and all manner of other vile acts.
A character afflicted with this derangement is always "on the prowl" and shoul dattempt to consummate as many relationships as he or she can, according to his or her orientation (which may well change over the course of the chronicle). This derangement has no mechanical effect; it is included as a curious condition rather than a dice-goverened system.