I have no dog in this fight, but let me pose a hypothetical situation to you...
It's true that many trannies look much better than genetically-born females. Let's say you met a hot chick...I mean...super hot...great body, face, sculpted fake breasts, etc... and you started dating her. At some point, say...a few weeks in, you've had sex with her a few times...and then she up and says..."I have something that I think you need to know...."
Cop-out answers include "I would be able to tell..." because you can't.
I assume you'd break up with her, but would you be ashamed, or anything like that?