Prolonged sex itself usually does not directly cause vaginal looseness. The elasticity of the vagina is determined by the health of its muscles and tissues, which can typically return to their original state after sex. Vaginal looseness is more commonly associated with factors like multiple childbirths, aging, or lack of exercise, rather than the duration of sexual activity.
However, frequent and overly intense sex can lead to temporary physical fatigue or discomfort, especially if there is inadequate lubrication or excessive friction. If vaginal looseness is a concern, it is recommended to perform pelvic floor exercises (such as Kegel exercises) to strengthen vaginal tightness and elasticity. Additionally, maintaining proper rest and communication can help maintain a healthy sexual life.