This is a fun question.
In my world vampirism is a disease spread through blood contact. Vampires are human, just with a select set of symptoms associated with their disease (light sensitivity, heightened sense of smell, weakened immune system, and, not an effect of the disease itself but of its treatment, a slowed aging process). As such, they can procreate with humans or other vampires, but generally choose not to, especially in the case of the mother being a vampire. Both because of the risks to an infected woman and the baby during pregnancy, and the fact that the baby would likely be born a vampire, it’s generally avoided if possible. Of course, there are still plenty of children with one or two vampire parents.
As far as sexuality and sex in general, it’s pretty much the same as with humans. A vampire’s orientation doesn’t change when they’re infected, nor does their view of or willingness to have sex, unless the switch to the will-burn-up-in-direct-light-without-this-cup-of-blood lifestyle happens to. My main vampire, Xam, was infected by his now-ex-girlfriend, a vampire named Jordan, several months into their relationship, and they had been having sex before this without Xam experiencing any dangerous or vamp-y effects. Though it sort of killed the relationship for them, considering Jordan considered her spontaneous decision to infect him romantic and Xam didn’t, Xam’s vampirism hasn’t changed his sexuality at all. However, it has put a damper on his thoughts of children. He doesn’t like the idea of living decades longer than his children, considering his prognosis is close to 200 more years, and considering his current very serious girlfriend is also a vampire he doesn’t want his children born with the disease or to put her through the dangers of pregnancy.