Let's say your loved one or spouse just passed away recently.
Let's say they came back as a ghost. Let's say they were good at being a ghost and you could occasionally feel their body against yours.
Let's say they wanted to have sex with you. Could you do it?
Hmmm... long as she assured me she couldn't/wouldn't have little Caspers flying around after sex- maybe!!
What if you found out your significant other was a vampire? And for some reason you couldn't become one yourself because of your blood. Would you stay with that person? Knowing that they have many lovers in their past and would have many lovers in the future?
Depends- if I were to ask her what people taste like when she bites them... and she were to say: "they taste like chicken"- I'd know she at least has a sense of humor- so it's possible!
The second half of the question is irrelevant because most people would have had partners before you and most likely will, after you!
Best I can do on such short notice!!!