^ I have to agree.
He has told Elizabeth time and time again that he is loyal to her - that he has only ONE queen and ONE country that he serves. He just wants peace... and he's not above manipulating Mary and her feelings for him to get it.
You have to hand it to him... the floating bedroom is pretty romantic. I can't imagine Mary actually saying yes, though. To me, the look on her face in the promo just says, "Aww. That's so sweet." We'll have to wait and see how it plays out.