"If I had a brother or sister, I would be able to live like a princess...""Does your love for your sister cross over into some sort of incestuous sister complex...?"
"Incest is normal for vampires."
"...Huh?"Reproductive ability is not a strength of our species. There aren't a lot of vampires, you know. So in order to keep the bloodline pure, parents and sisters and brothers...""So in the end, what are you seeking from the love with your sister?""Ah, calm down..."
"...I'm nervous."
"Are you alright? How about I unwind you?"
"Hey, cut that out.""So, what if Flandre were a boy?"
"Of course, for the good of the species I would offer up my body."
"Vampires sure are dark creatures..."
"You're the same, aren't you?""...What an unexpectedly lonely person.""I said that, didn't I? There aren't many vampires. The love for my sister is one for family, one for someone of the same species.""S—so you plan on making children with Flandre!?"
"Idiot. Vampires have a lot of powers, but two women can't make children.""Patchy and Sakuya. I've been able to make friends, but Flan is the only other vampire. The only other family member."