Why is it surprising that straight guys are attracted to people who look and act like women?

Sorry for the trivial comparison, but imagine a guy on social media to who portrays himself as 6'2" but is actually 5'8". He takes pictures to make himself seem taller. A woman who may have only engaged with him because he is tall and they prefer tall guys would be disappointed in meeting them.

Sure, there are transphobic people out there; a lot. That being said, thinking your GF is a woman and falling in love and then learning that she was born male is like ultimate betrayal. It doesn't mean they're insecure or not accepting, just they've been lied to, when trust is one of the most important issues.