The Mysterious Girl

"The Mysterious Girl: A male who desired intercourse must pass through four stages of attainment: elongation, swelling, hardness and heat.
Yellow Emperor: What do these attainments mean?
Mysterious Girl: If the stalk does not attain sufficient elongation, the man’s vital energy is too depleted for the act. If he attains elongation but little swelling, this means that his muscular energy is insufficient for the task. If he achieves swelling but not hardness, it means that his joints and tendons are too weak for the act. If the organ gets hard but not hot, then his spirit is insufficient for the act. In order to prepare properly for sexual intercourse, you must first harmonize your muscles and bones with your energy and your spirit (i.e. harmonize three treasures). You must also exercise self discipline, follow the basic principle of Tao, and never waste your semen carelessly."
by Bernard Atmovaibhav