No and no. First of, if you plan to date this person and the person is a male, you have to recognise it, even if before it you presumed other gender. You still be a lesbian even if once you were attracted to a man. I will copy-paste a text from a DroptheL/DroptheG vs. DroptheB/DroptheT discussion:
The freedom to self-identify our sexuality is incompatible with the freedom to self-identify our gender, because the freedom to self-identify our sexuality assumes that we can know or decide the gender of other people, and the freedom to self-identify our gender rejects this assumption.
If we are committed to gender self-determination, we must reject sexuality self-determination.
(To be precise, this limitation is not on «whom one is allowed to be attracted to», but rather «what name is acceptable to give to this particular pattern of being attracted to others» - note that there is no particular restrictions of this sort to place on asexuality.)
And even aside from that, all arguments about why "I would never date a fat or [insert non-white race] person" is bad also apply to any of the infinite genders and every possible body type that they might occupy.
So, you still be a lesbian if you acknowledge your attraction is flexible. Don’t enforce gender into people. ~ ap
