Hookers, brothels, strip clubs, and depictions of sex are all very common, especially in Pattaya and Bangkok. Even in the airport when I arrived, there was a mural on the wall that emulated old murals, and it essentially depicted an orgy. All of this stands in stark contrast to the rest of Asia. Pornography is highly illegal in China, sex is taboo in Japan...everywhere else in Asia is much more conservative. Not only that, but the sex culture in Thailand is very clearly open to all genders and sexualities -- the ladyboys being a particularly notable example of this. Is all of this a recent development? If so (and if this question doesn't run afoul of Rule 3), what are the native Thai perceptions of this development? What specific historical events and circumstances have resulted in the vibrant, sexually permissive culture of modern day Thailand?
I am not going to talk about Thailand here since it’s not a topic I am the most well-versed in, but I just wanted to point out for clarity’s sake that Thailand’s views do not actually stand in as stark contrast to the rest of Asia as you think. Particularly in the rest of Southeast Asia in general, sexuality was treated a bit differently than in East Asia. Notably, the Philippines and Indonesia both have similar histories of acceptance of multiple genders, if not even stronger ones (considering the roles of the indigenous religions and political structures that allowed for women and third genders to be very prominent). The Philippines in particular is certainly more gender-equal than anywhere else in Asia (and indeed, most of the rest of the world) other than maybe Taiwan, and the relationship with LGBT, though complicated at times, is also in better shape than in the rest of Asia (and is considered one of the most gay-friendly places in the world in general), again with the possible exception of Taiwan.
I’ve written some on this topic regarding the Philippines previously here.