How to stop penis shaking if he has a habit of it from when he was14 year old & now he was 17 year old 1?

Here are some... I assumed "penis shaking" means masturbation. Marching into adulthood - roughly 18 for men, denotes physiological readiness to mate for reproduction has arrived. Orgasm may be considered as incentive compensation to drive mating process. If not in mating, men masturbate as deviating way to mentally fulfill the pleasure of orgasm which may lead to obsession for some. Otherwise, ok to masturbate...