To be honest, despite the fact that the Nancy/Nova scene was hot, I didn't liked it very much. The solo scenes where much better - in my opinion.
It's quite some time gone sind I played the game last, but from what I can remember was that this complete talking about threesomes or other stuff, with nancy watching, was to much out of character from Nancy.At least in my head canon was this way to suddenly and forced.
Nancy's complete behaviour prior this scene was total different, that was more like a 180° turn. That all would be more believable if Nancy has shown in the earlier versions of the game a glimpse of this kinky side of her.