Confusion

I talked to The Youngest today. John was a guy who graduated a year ahead of her. John had a sex change operation and is now Sue. Sue is 'married' to Debbie. This came as quite a shock for The Youngest.

This thing leaves me with a few questions. Now, I'm not going to pretend that I understand someone wanting to change their gender, but whatever. The biggest question I have is this: If you change from one gender because you feel as if you are the other gender, why would you go through with the operation and be a homosexual after wards? From what I understand, a person has to go through intensive psychological testing and therapy before a doctor agrees to the operation. Now, if a person feels as if he/she is supposed to be the opposite sex and identifies with the opposite sex, doesn't it stand to reason that the person is attracted sexually to persons of the sex he/she was born as? I mean, to BE a male means being attracted to women and to BE a female means being attracted to men, right? So, to be a male wanting to change to female would mean the person ALWAYS is attracted to males. Before the operation the person would be gay, but would be 'normal' after. If this isn't the case with a person seeking a change, then why would a doctor accept the person's saying he/she has always felt wrong in his/her body and KNOWS he/she is supposed to be the opposite sex? What am I missing here? This REALLY confuses me.

Okay, so maybe John and Debbie were married before he had the operation. But now he is a woman--legally and in every other respect. It is not legal for two women to be married, so how can they still be legally together? Was their marriage automatically annulled as a result of the operation? Way, way, way too many questions. Maybe I should just quit thinking about it--it makes things that much easier.