Difficulty getting an erection after ejaculation is due to the presence of the male refractory period, which is a normal physiological phenomenon. The male refractory period is the interval between the end of a sexual intercourse and the time when the body is ready for the next one. It begins with ejaculation. After ejaculation, the penis is in a state of weakness or semi-weakness, and even stronger sexual stimulation or friction cannot cause an erection, and sometimes the penis is in a state of semi-erection, but it is still not able to complete ejaculation again. The duration of the male refractory period varies from person to person, ranging from a few minutes to a few days, depending on factors such as energy, age, stamina, etc., as well as the mode of sexual stimulation and sexual partner. It is a physiological mechanism that protects the man and allows him to be sexually active even after the period is over.