User blog comment:B214/Question and Answers 2/@comment-187.195.197.49-20140430172611/@comment-3965848-20140430205129

You know I think that she's made some progress in "getting close" (and I mean sexually) enough with Issei without falling, like how she was in the same bath with him and made no indication of her wings flickering from white to black, nor did it when Rosswiese asked him to her boyfriend.