First 性的强势和弱势之差 is the source of evolution The beauty of evolution is, no matter what 观点不敢认同, as far as it exists, it is the truth.

However, you have a point, 不危害第三方 is a tricky standard, even FZZ cannot explain it clearly. There is no completely isolated system, anything has its consequence. And sex behavior the effect is usually very large.