Obviously, Lestat isn't straight. As he Declares his love for Nicki and Louis. It is implied heavily that Lestat and Nicki were Lovers when they were Mortal Men, he also heavily implies that he had multiple lovers of both sexes as a mortal man. It is also implied that Lestat and Louis were lovers. So does that mean that a Vampire within this universe is capable of having sex? It's not explicitly written either way. It is written (SPOILER) in Prince Lestat that Seth and Fareed give him an IV that allows him to "achieve completion" of a sexual act with a mortal (eventually creating his son Viktor.) Without this Medical Intervention can a vampire have sex? I'm trying to write a fanfiction and it's incredibly difficult because I'm torn as it is not EXPLICITLY WRITTEN in this universe that they either cannot (as logically no bloodflow = no erection) or that they can.