Why Is Masturbation Sin?

[Anomalocaris]

I know a lot of Christian masturbaters, so I have no idea why we're even having this conversation.

Christianity and Islam are essentially mental masturbation rackets with an utterly unscrupulous own-marketshare-at-all-cost-to-society business model and frequently murderous monopolistic bent, So naturally they can not abide by competition with a physical advantage. This is why they deem physical masturbation sinful eventhough their own forms of mental masturbation have been murderously and comprehensively harmful everywhere they are practiced, whereas physical masturbation has never been show to have anything like.