The combination of yin and yang in nature is more harmonious. Most places are done by women, but now men's jobs may be commercially attractive, and everyone may be curious and want to experience different feelings. When a man does it for a woman, the human body may have some other reactions to achieve better results, while a man may do it better if he is meticulous and clever. As long as everyone has a correct mind and doesn't entertain foolish ideas, there is nothing wrong with looking at this problem with a scientific attitude.