When a 60-year-old man is unable to enter the vagina smoothly during sexual intercourse, the main considerations are related to vaginal dryness, erectile dysfunction and other factors. 1. Vaginal dryness: when having sex, insufficient foreplay leads to vaginal dryness in women, which instantly leads to the phenomenon of not being able to enter the vagina smoothly. 2. Erectile Dysfunction: Erectile dysfunction, such as weak erection and short erection time, will also lead to the male penis not being able to enter the female vagina. 3. Other factors: If a woman has congenital narrowing of the vaginal opening, or the vaginal muscles spasm due to emotional excitement, it will also affect the normal sex life, and the penis will not be able to enter the vagina smoothly. The reasons for this situation are relatively complex. It is recommended to consult a doctor in time for examination, after clarifying the cause of the disease, to be targeted treatment.