Cultural, social norm and to a limited extent of each individual..the social acceptance of a practice that deviate away from the normal man-woman relationship is seen as abhorrent in an Asian conservative society.
The world has evolved to this day. The very moralistic lives of each of us will really depend on our very own interpretation of our values and acts. Each country tolerates differently 'adnormal' sexual practices. Some countries even approved it as normal. Some closed an eye to the love in 'isosceles' tolerance. The world is changing fast and furious! New York approved same sex marriage!
S'pore is an Asian country not as liberal as our western counterparts, hence the law, the people's view of sexual deviance as something not within the normal practice of natural sexual 'coitus'. It may take time to understand the emotional needs of individual living in a body shell not their own and their sexual preferences. Society needs broader understanding and study into such behaviours.
Having said that, if force is used to achieve a sexual desire, be it natural or 'unnatural' is definitely against the framework of the law.
We must differentiate between the circumstances..." As men are not creatures of circumstance, circumstances are the creature of men" -- Benjamin Disraeli...
patrick lee song juan