You've just met Joe. You wouldn't ask him how he has sex...so why would you if you knew he was transgender? End transphobia. Follow this link to find an insightful short clip featuring a number of trans activists answering the question, "How do you describe your gender identity?": http://www.thesociologicalcinema.com/1/post/2012/05/how-do-you-describe-your-gender-identity.html
Anxiety Transgendered individuals on a daily basis-- as well as the fear of harrassment and violence, which adds up to an astounding number of one murder of trans every three days. Does it even sound right to you? It all comes down to basic human rights.