The sperm go into the female partner's vagina. Male fertility depends on your body making normal sperm and delivering them. Semen then travels through the urethra and out of the penis. When you ejaculate, the sperm mix with fluid from the prostate and seminal vesicles. There each vas deferens joins the ejaculatory duct from the seminal vesicle.
Each vas deferens leads from the epididymis to behind your bladder in the pelvis. Just before ejaculation, the sperm go from the epididymis into another set of tubes. When the sperm leave the testicles, they go into a tube behind each testicle. The testicles are in the scrotum, a sac of skin below the penis. Sperm and male sex hormone (testosterone) are made in the 2 testicles.
Chemicals in your body called hormones control this.
The male reproductive system makes, stores, and transports sperm. During sex, ejaculation normally delivers the sperm into the woman's body. The man's body makes tiny cells called sperm.