Bloody HELLTHY

A vampire named Collin, who doesn't drink blood, accidentally tastes Ian's blood. Enthralled by the sweet taste of it, Collin losses his rationality and attempts to attack Ian but fails. Feeling guilty towards Collin's mistakes and experiencing hunger, Ian decided to make a small condition and promises to offer his blood. However, through the contract of blood-sharing, their relationship evolves beyond mere thirst into something more intense… "What should I do… I really really really want Collin…!!!"

(Source: Mr Blue, translated)