Hello dear Understand your concern. It is difficult to say what is the cause. You should consult the gynecologist and go for proper examination of pelvic area Cause may be: Spasm of vaginal muscle Lax vaginal wall Vaginitis Vaginal infection: candida, trichomonas dermatitis Urethritis Hygiene problem Advice: Maintain hygiene after and before urination and sex Wash vagina with salt warm water 4-5 times a day Use liquid nonperfumed soap Wear loose cotton inner wear Change inner wear after workout If not resolves consult the gynecologist and do the test for above causes.. Hope this may help you Best regards Dr. Sagar