"I conclude from the above that, in the west, people are free to marry their mothers, fathers, sisters, brothers, sons, daughters, monkeys, pigs, lamas, mules...etc"

No, people in the West aren't free do to those things, as A) you cannot marry someone who cannot consent to marriage and B) Incest is illegal due to problems with birth defects and that it's usually non-consensual.

I don't care who marries who as long as they can consent of their own free will, and are at the age of consent.