I just think people of this forum of all should see that there is more to gender identification than what sexual parts person has, otherwise the whole theatre about calling ourselves girls is stupid.
I think if somebody makes a convincing girl there is a good chance that she will attract straight men as well, if they find out about her "lower parts" it most likely will discourage them from further progress, but they may
still find a sexual way as sex can be very diverse thing.
Judging someone's sexuality purely on the physical sex attributes i think is a bit short minded. As in your example you like your man because he is a man, if he presented himself as a girl he might not be so appealing for you.
For me it's also important that my girlfriend is at least bi-curious , as if she merely tolerated me as Matia, I don't think it would really work for either of us.