The Deep Series by Z.A. Maxfield

There's no leverage like seduction...until love takes a big bite out of Adin's plans.As the Indiana Jones of historical erotica, there is no document Adin Tredeger can't unearth. Why he would risk the biggest coup of his career to join the mile-high club is beyond him. Nevertheless, the disarming, dark-eyed vampire Donte somehow enters Adin's locked airplane washroom and has him completely nude and coming apart, all without a whimper of protest... moreThere's no leverage like seduction...until love takes a big bite out of Adin's plans.As the Indiana Jones of historical erotica, there is no document Adin Tredeger can't unearth. Why he would risk the biggest coup of his career to join the mile-high club is beyond him. Nevertheless, the disarming, dark-eyed vampire Donte somehow enters Adin's locked airplane washroom and has him completely nude and coming apart, all without a whimper of protest.From that moment, Adin and Donte engage in an international battle of wit and cunning. The prize is a priceless 500-year-old journal with illustrations so erotic the Marquis de Sade would blush.
Yet Donte's desire for the journal goes far beyond simple possession. He wrote it. And he's not above using every trick in his otherworldly arsenal—including seduction—to get his journal back.
Chemistry draws them together even as fortune tugs them apart. When a third party enters the chase, will Adin and Donte join forces to fight an enemy with a deadly goal—to erase Donte from history forever? less

Donte won't be happy until his fragile human lover is immortal. Adin won't be happy until Donte accepts that immortality isn't for him. After a case of mistaken identity leads Adin to what appears to be the sale of an underage boy named Bran, Adin decides to rescue him and turn him over to the police. Soon it becomes clear that Bran is no ordinary boy. Unless Adin can find out who wants him and why, someone else's plan for Bran will get them both killed... moreDonte won't be happy until his fragile human lover is immortal. Adin won't be happy until Donte accepts that immortality isn't for him. After a case of mistaken identity leads Adin to what appears to be the sale of an underage boy named Bran, Adin decides to rescue him and turn him over to the police. Soon it becomes clear that Bran is no ordinary boy. Unless Adin can find out who wants him and why, someone else's plan for Bran will get them both killed. Adin is confident -- but he's not stupid -- and it doesn't take him long to realize that he'll need Donte by his side every step of the way, if only to answer the one question he asks himself more and more: What else is out there? ( This is the Sequel To Notturno) less

Forever is a long time. Even for a vampire. Deep, Book 3 When Adin Tredeger discovers his lover Donte's role in turning him into a vampire, he's outraged. The opportunity to attend Ned Harwiche's funeral is perfect for putting some distance between them, but as a newly turned vampire, he mustn't go alone. Cristobel Santos - one of Donte's lifelong enemies - and an attractive Irish vampire named Sean offer to chaperone his trip. They are as determined to help him as he is to reject their aid... moreForever is a long time. Even for a vampire. Deep, Book 3 When Adin Tredeger discovers his lover Donte's role in turning him into a vampire, he's outraged. The opportunity to attend Ned Harwiche's funeral is perfect for putting some distance between them, but as a newly turned vampire, he mustn't go alone. Cristobel Santos - one of Donte's lifelong enemies - and an attractive Irish vampire named Sean offer to chaperone his trip. They are as determined to help him as he is to reject their aid. While Adin fights his new reality he's kidnapped by rogue hunters and used as a lab rat in some skin-searing experiments. Adin's distress electrifies his connection to Donte, but rescue is only the beginning.... Warning: Hot vampires, spoiled teens, big cat shifters, and two men trying to figure out how to squeeze several lifetimes' worth of love into every moment of their big, fat eternity. Ouch.... less