Ok, so I thought Ciel being female was a complete secret known to like, a handful of people. How does this random guy know about it? And even if he does know about it, how could they marry as "husband and wife" if Ciel is meant to become the emperor? Surely his only use is to make sure that Ciel produces an heir. They still intend for her to present as a man to lead the country. And even disregarding that, how did that guy think it acceptable to speak to her the way he did? She's still the next in line for the throne.
I guess you can put it down to her intentionally submitting herself out of some desire to be punished, but it's still pretty insane for a Duke to speak to a royal like that. Honestly, the weird writing in this chapter was almost enough to overshadow the fact that Eve just fucking kissed Ciel.
That said, HOLY SHIT EVRIS KISSED CIEL HOLY FUCKING BASED. Also, the line:
Take responsibility for that!
Made do a double take, because I see that line a lot in regards to pregnancy. Which tells me that magical babies are something we should expect to see in this manga in the future.