This happens all the time. Like some classmate /lab partner/ coworker on some project. The gal who doesn't dress flirtatiously or even slightly flatteringly to any of her features. Usually don't make up their face. Not ugly but initially seen as, just plain. Not interesting enough to pique my curiosity. But a cool personality so you don't mind working with her. But as you work together in class or on the project week in and week out, you find not only is her studies/work ethic a turn on and her humor makes her attractive sort of But there's these little hints that appear like once she knelt down to pick something from a lower shelf and you get a quick glimpse of her little bit of backside revealing a little bit of some nice curves you never would have thought on her. Or one day she had her hair up so you see a nice neckline never seen before or once you went up to her to ask about something etc regarding the lab project and when you tapped her arm you felt a hint of definition and the firmness of working out and taking care of herself. And one day you all go out at night when the class is over or the project is finished and lo and behold she dresses up and makes herself up like none other you have seen her before ever during the times you worked with her. And like you think " dam!I was working with one bombshell hottie!"