The OCC
I think it'd be fun for Misa to have always had a bit of a crush on Merlin but never brave enough to act on it, thinking he was way too good for someone like herself. Then before either she or Merlin could act on anything Jack comes into play as the dark horse to try to sweep her off her feet. Who know perhaps that will encourage him to make a move. Or not when he sees how happy she seem to be dating Jack. I love me a little bit of drama. :P