The liver meridian circulates around the vulva. The main muscle of the liver, in Huangdi Neijing, male genitalia is called "Zongjin". Zongjin means a gathering place with many tendons, and it also means to carry on the family line, so as the saying goes, men are afraid of hurting their liver and women are afraid of hurting their kidneys, which is what it means. The liver is the gathering place of human yang, and the masculinity of men is bound to be born from it, so people with a strong liver are usually more sexually capable. But the function of liver and kidney must cooperate with each other to be lasting and harmless. If the liver is a gun, the kidney is ammunition. Whether it can be tough depends on the function of the liver, and whether it can last depends on the support of kidney essence. I hope I can help you.