My 2 cents worth,
Love and Sex. Two separate words. They may be, at some time,be conducive. But I think falling in love is different to falling into sex. When you truely love someone, that very special person, the sex bit works it way through. If the relationship is based on sex, well you girls and guys in the US have lots of examples from Hollywood. Doesn't work, to my mind.
Of course and not so far discussed is that sex is for procreation, and no I'm not a Bible pushing person ( sorry if I offended anyone). Cis girls at sometime in a relationship are (commonly) looking for a partner to father her children, Cis Guys may be less motivated in this but .... swings and roundabouts.
In a TG relationship this may not be an issue. Only trans women who have frozen down sperm and transmen who have frozen down eggs, will be able to have children, maybe. Yes we can adopt etc, but that's not the point of the thread. So sexuality for trans people may be a little different to that in the cis community.
Sorry if I'm rambling.
Love you Gals and Dudes.
Keeps me sane.
Now you know how scarey I am

Cindy