For all of the hareming and seduction attempts, it is interesting that not only is Ice still the only one that has actually shown herself naked to Touma, she was perfectly comfortable with it.
It's because he very clearly has depression and is making no effort to hide it, while she likely also has depression and is only making enough of an effort to hide it that he doesn't notice.
He and Negi seem to like each other well enough, and them hooking up might actually genuinely get Noa to spontaneously combust into pure essence of drama.