Where does all the semen go to when I don’t masturbate?

Only 1-3% of the semen consists of spermcells. Most of the fluid comes from the prostate and seminal vesicles. This fluid is only secreted when you are excited and are ready to ejaculate. Spermcells are produced every day. If these are not released in due time during masturbation or sex they are broken down and the nutrients are reabsorbed by the blood.