It could go either way, as I indicated in my response. Most rapists and pedophiles are habitual masturbators. But not all people who masturbate are rapist or pedophiles. Like a lot of things, one act can lead to another, but not necessarily. For instance, most heroin addicts started using marijuana, but not all users of marijuana become heroin addicts.
Masturbation requires one to fantasize and to lust, therefore sin is involved.
A single person cannot commit adultery with another single person. So this verse would say a single person should not lust after another person's wife. But I don't think the natural desires that a single might feel for another single is being referred to in this article. And such desires can be the source of masturbation without it being an addictive lust. Self-stimulation hardly seems to be using one's members as instruments of righteousness.