Did you know - AMERICAN BUKKAKE has recorded over 2,387 cum shots since its inception? Ejaculation, like an erection, is basically a spinal reflex. The length of the average ejaculation is 3 to 10 seconds. The amount of semen a man ejaculation is influenced by a number of factors: 1. The length of time since the last ejaculation. 2. The duration of arousal before ejaculation. 3. Age (older men tend to produce less fluid)