Lupe Delgado was one of the co-founders of Home, along with Rowan Magruder. Donald Callahan fell in love with him, despite both of them being primarily heterosexual. He is not related to Susan Delgado.
He was bitten by a vampire and contracted AIDS as a result. Seeing Lupe being attacked started Callahan's killings of vampires. Callahan's vampire slayings would in turn draw the attention of the Can-toi.
Lupe would later die from his AIDS infection.