Ejaculation for men is orgasm, you can't have a full orgasm without ejaculation.
When doing sex magic orgasm is extremely important as orgasm is where the sexual energy you are directing during the sex magic ritual are being released. At the moment of orgasm gather the sexual energy and form it into a ball, then program whatever you want the energy to do, such as making your crush feel attraction towards you, or attracting a soul mate, or even something such as empowering a chakra, healing your self or a loved one of illness.
Sexual energy can be used for pretty much anything and is the most powerful energy that we can use second only to the energy of the Kundalini itself. Mastering the use of sexual energy in ritual to empower ones magick is essential to raising the Kundalini and can make you immensely powerful even without raising the Kundalini.
So while building up to the orgasm vizualize your goal, or what you want this energy to accomplish and when you have the climax of orgasm, gather the sexual energy that is released, form it into a ball and state your affirmations to program it, then send it where it needs to go.