It's something that would really humiliate Mion. I would only use it in the most extreme circumstances.

[ He gets up on top of her, letting his hands roam her body. They start innocently enough, stroking her shoulders and arms, but soon, his fingers are grazing over the exposed skin of her breasts, and his lips move to brush against her ear. ]

How would Mion like it if I screwed her somewhere where someone would definitely see...?