He watches her move her hand up to her mouth, and his grin only grows bigger at that. He can't help it, he thought she was adorable when she did stuff like that- even if she tried to hide her embarrassment with that deadpan expression. Amakusa was excellent at reading people, so even though she was mostly always monotone, he could tell when she was angry or flustered. He thought she was cute whatever she did but...

"What? You've never heard about making a demon or something your familiar?" Amakusa chuckled at that, "oh lady- and here I thought you knew all about the occult. When practicing magic way back in the days of knights and whatnot, they used to do that to acquire a familiar. Just a kiss, and it wasn't always human looking either. A toad, or a dragon- but whether it's on the lips is a different story. I'm your bodyguard in the human world, but in the meta-world, I have no obligation to be around you."

...Oh that sounded kind of rude, "ah, I didn't mean it like that. I like you a lot lady- I already told you you're the one who's captured this wild guy's heart. But... I don't want to be furniture to lady Bernkastel and lady Lambdadelta anymore. They never made an official pact with me, so if I'm yours... do you see where I'm going with this?"

Yes he was basically asking for a kiss here as well.