use the muscle you would use when you urinate.First ,when peeing stop the flow of urine,this is your kegal muscle.Next ,flex this when you are jerking off next time,keep doing this ,even when you cum to the point of ejaculation.Noice how this feels,keep doing this while jerking off,practice makes pervert

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As for cum increase I use natural foods ,like pumpkin seeds,pygeum bark,and lots of water.