Groin pain after ejaculation may be related to improper posture, seminal vesiculitis, varicocele and other reasons. 1. Improper posture: If you have improper posture during ejaculation, such as over-extension of the lower limbs, leading to strain of the inguinal ligaments, you may feel pain in the groin after ejaculation. 2. Vesiculitis: If you suffer from vesiculitis, you need the seminal vesicles to secrete semen during ejaculation, which will make the seminal vesicles active, and because the seminal vesicles are stimulated by inflammatory factors, the local nerves spasm, and when the local nerves are involved, you can feel pain radiating to the groin. 3. Varicose veins: when the varicose veins of the spermatic cord, can lead to the spermatic cord is stimulated and produce pain. And because the spermatic cord passes through the inguinal canal, it can manifest as groin pain after ejaculation. If you have pain in the groin after ejaculation, you should go to the hospital as soon as possible, and the doctor will formulate a diagnosis and treatment plan according to the specific condition.