Since I don't really get it I'm just gonna leave this here.
(right bubble) 　あなたの首はいらないよ！
(left bubble)　いなくなっちゃうのいやだもん
Hope someone can make good use of it.

Cute and creepy according to her species.

Is she talking about circumcision?

Huh, she's actually swearing to reject her killer nature. Cute contrast with the ones like Rumia and Letty implying that the relationship might not be that safe.