This question has surely been asked dozens of times and in spite of that - it seldom gets answered correctly.
Why? In the first place most people think that since ladyboys are technically still men, especially those who still have their male organs (pre-op), and they like men - therefore they're gay.
Strangely enough this view was even echoed by a Thai male who needed some gay people for a photo shoot or something and said he would get some ladyboys! This shows how misunderstood this is even in a country where there are literally tens of thousands of ladyboys in the population.
Nothing could be further from the truth. In appearances, behaviour and oh gosh they even drive like women! (I know, I was driven around by one in KL once.) It's all 100% woman and even down to their thinking.
So, them liking men makes it a heterosexual relationship! Simple and straightforward!
Questions anyone? I know there's bound to be some.