The Undead Kama Sutra — Mario Acevedo

Ex-infantryman Felix Gomez came back from Iraq decidedly undead. Back home in Denver, he embarked upon a new career where nighttime work is the norm: private investigator. Since then, he's managed to survive lustful extraterrestrials, manic nymphomaniacs, and x-rated bloodsuckers, while satisfying his own unorthodox hungers with blood-laced Mexican food. But some thirsts aren't as easily assuaged, and that's where “The Undead Kama Sutra” comes in … a hands-on manual that illustrates how sex can help a lonely vampire increase his psychic energies
Felix's search for missing parts of the coveted manuscript is, of course, purely professional. And now the dying words of an alien interloper (“Find Goodman and save Earth's women!”) are thrusting the immortal (if he's lucky) P.I. and a bodacious undead sexpert, Carmen Arellano, into a seamy mess of otherworldly abductions, shady military irregularities, and unexplained murder.