Succubats normally only live short lives, only a couple years even in captivity, but by pairing with a symbiont, they can live for as long as their partner.
No, sexuality has nothing to do with gender. Succubats don't care about your sexuality and, for an example, if a host only liked men, they'll still only be into men.
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So does the sexuality also play a part in determining the gender of the simbiont ?