How do you know if your seminal vesicles are full?
As your seminal vesicles, the glands that produce semen, fill you desire for sex rises. At some point thoughts about sexual things constantly interrupt your thoughts. If you are able to wet dreams, it is usually about this time that you have one. If you don't, then the thoughts about sex get increasing frequent. You might find yourself doing usual things, such as wanting to take off your clothes or putting your hands down your pants when you aren't thinking. Eventually when the seminal vesicles get so full that you can't hold anymore semen, you will have a spontaneous ejaculation.