[That's the kind of reaction he was expecting, though Juno's choice of retort has Ren letting out a rather theatrical sigh as he flicks his fingers and one of the tentacles comes forward to touch at Juno's cheek. It's sort of a prodding, experimental motion, and Ren's watching Juno's expression rather closely to see if he reacts more visibly.]

If you say things like that, I'm going to take you at your word. You know that, right? So you'd better be really sure that you mean it.

[It's about seventy percent playful to thirty percent a legitimate warning. He doesn't want Juno to try and bravado his way through when he's really not enjoying himself, because that would just make it regrettable for both of them.]