Dear service user, Thank you for writing to healthcare magic. Let me tell you young friend that there is no such thing as excessive masturbation or over-masturbation. Just as excess of sexual intercourse cannot lead to weakness, so also excess of masturbation. Sexual intercourse is not BAD HABIT, so also the masturbation. Masturbation in private or with a partner is generally considered a normal. Masturbation is akin to sexual intercourse. What penis does in vagina during sexual intercourse, same it does during masturbation in your folded palm. This is a natural activity and I would say a healthy activity and does not either affect or deter sexual performance. It is myth that masturbation causes impotency in future. If masturbation becomes habit or if one has to do it rather than doing to get pleasure, then you should get medical advice from psychiatrist to come out of the problem. Behavior therapy, counseling with anti anxiety medications are together helpful for similar clients. Penis size has nothing to do with sexual satisfaction of either partner. Go ahead. Wish you good health.