Two things:
Love this manga a lot. It's very erotic, the relationships are a little messy in a fun way, and it's better than a lot of hentai that have NTR where the person who is getting cucked is being cucked against their will. A good view of non-monogamy here in my opinion.
Vampire-san Wants Her (Man's) Blood Taken is what the English title is written as. But I think it should be Vampire-san Wants Her Man('s Blood) Taken. The current wording makes you think she's getting her blood sucked.