Maybe I'm just being dumb, but I don't see the similarity between someone who intends only to harm another using violence, cruelty, with the ultimate objective of ending a life, and someone who wants to live life to the full, being a productive, active, contributing and integral member of society through the simple act of correcting a defect they were born with in order to do so.
Call me naive, but I always thought you fall in love with the gift, not the wrapping. And if the relationship was perfect to start with, why would any revelation about who a person used to be change that? They aren't that person now, and they weren't that person when you met. I mean, using that logic, why do you not see them as a snivelling three-year-old wearing a diaper and snorting milk out through their nose? After all, they used to be that, too. It doesn't make sense.
Unless it is purely the physical lust that drives the relationship... in which case, it would be far too shallow and superficial to be anything close to perfect in the first place.
People are people, with the same capacity to love, care, trust, feel, hurt, hope, dream ect. The process of physically altering one's outward appearance to fall into line with one's inner self-image takes none of that away. In fact, it could be argued that through such persistent self-awareness, such emotional capacity is actually heightened.
My own view, transmen or transwomen... aren't any less men or women because we were unfortunate enough to be born with the incorrect anatomy. It just means we've had to work a little harder to be ourselves. Ourselves having being there all along. If you fall for a transwoman pre-transition, she's no less a woman. Post-transition... likewise. The heart, soul, spirit, desire, capacity for human interaction: all female... even if, pre-transition, the external appearance is ostensibly male. The essence of what makes a person isn't based solely on the sack of flesh they walk around in, no matter how attractive that may or may not be.
Just my thoughts. 🙂