[Mipha waits, listening patiently as Mephisto speaks (although there's a noise of protest at first when he comments on it being a terrible decision, but she goes quit afterwards).

She's been holding her breath a little throughout it and it all comes out on a rush of a sigh as he finishes.] Oh. [This was one of those 'hope for the best but prepare for the worst' situations, and she hadn't quite expected it to get this far... So she had nothing planned on how to respond to actual acceptance and reciprocating feelings.]

I won't force you to change for me, Mephisto. I won't ask for that. But, I... [Mipha laughs a little and looks embarrassed] I'm really happy, but I don't know what to say. [So she reaches for him instead, just wanting to be closer for now] I want... you. Just you. Flaws and all.