I read this years ago, not sure if it was here or elsewhere. I don't remember much other than it eventually bugged me enough to stop reading, but now of course it's stuck in my head.
All I really remember is the male MC was autistic and built and good at martial arts. I'm betting his autism wasn't handled well but that might just be because it hardly ever is rather than an indictment of this particular story.
Anyway. The female MC was his best friend since childhood and she called him frog or toad or some such because she still saw him as the gangly teen she used to know. Then someone told her to really pay attention during one of his fights, and she was immediately hot for him. Because of course she is.