ladyboys

okay I just watched a show on the television about Lady boys. It was a fascinating documentary about life in Thailand . A term or reference that I had never heard of until tonight. Yes I have seen and known the few that have been locked into the wrong body {gender|}
My question that I put out there is I would like to know more about these ladyboys and anyone that has been involved with one, knows one or is one. My main reason for this question is obviously ignorance, so I want to learn and understand. My understanding of what I watched tonight is; they are (from what I watched) young slender built people. Are they a female locked in a male body? Are they clever young men channeling into a lucrative money making business to feed their families via the diverse and perverted western world society? I do not know that is why I purpose this question out there. One of the things I noticed or took from this show was that they the (ladyboys) were prepared to do.They were concentrating on their body and looks externally to be beautiful and stunning looking women.  concentrating on their hair, makeup, clothing and growing boobs. but they wanted to keep their penis's. why? If you are a heterosexual male  that falls for one of these females that still have a penis, then how do you explain this sexual relationship. As a male you have been attracted to the female looks and seduction, as you become intimate as a male are you suddenly gay? the top part of the body and externally to the outside world you are with a woman, under the covers what does happen? Would love to learn more from others that have or are in this situation,