Natural Law and Sexual Ethics

Lol at leaving out the last bit of the title.

Natural Law is the biggest pile of bullshit I've ever seen. It always comes down to Person A saying "the purpose of X is Y and Z. Anything else is unnatural!" Then Person B says "no, the purpose of X is Y and Q. Quit arguing with nature!"

The only way for this to work is if there were a unified list of every person, place, and thing along with the accepted functions of each.