There are combinations to consider... a fantasty can be about anything and it doesn't change who you are or what your orientation is. Or if it is about your identity... Suppose you are straight...that means no same sex partner, but suppose you consider yourself to be female sometimes and male other times... Then maybe you are still straight because your orientation changes to match your identity. You could also be straight and lesbian too...which means you're not in to guys at all, but maybe you can still fantisize about being female which includes feeling like a woman and being treated like one.
