This is from my hubby, re: your email about your son reaching puberty, and in particular the challenges of the m- word habit.
Here are my thoughts that you could pass on to the mom and her husband. It seems to me that she is right on (to want to give attention to this issue), but her hubby should be the primary one to discuss this with their son. It would be healthy and good for all three of them for the boy to be working this through with his father — and developing an accountability system with his father (who has "been there" and may sometimes still be there).
Yes, it (masturbation) is basically unavoidable, but the way in which one processes it is very important (i.e., whether it remains simply a physical outlet with no guilt and no entertaining of lustful thoughts), and the self-control aspect is a noble and often achievable objective in that regard. One can control it, and it's important to, because m. is addictive and can result in guilt and antisocial behavior. Not lounging around in bed once one has awakened is a key thing. Often, a guy awakes with an erection, and that prompts the m. activity. So, to just right away get off the bed and down on one's knees to welcome the new day and acknowledge the master is a wonderful start. Here's what I generally say:
Also: Dad can explain nocturnal emissions ("wet dreams") to his son — that the Creator built in a mechanism for release even while he is sleeping. Nearly every guy experiences this at one time or another, and it is a totally natural occurrence. It's nothing to be ashamed of. It is most frequent during the adolescence of men — perhaps especially for those who through their godly self-control are not permitting themselves another outlet. It would be good for the dad to assure his son that if and when he awakes with semen on him and on the sheets, this is fine — it shows that all his parts are working great; the system is being flushed and is being maintained in nice working order. After it has happened, he should bathe himself with water (and wash the sheets). The Scriptures talk about it — Leviticus 15:16-17 and Deuteronomy 23:9-11 (where the phrase translated "nocturnal emission" literally means 'by reason of what happens to him by night').
A correlated father-and-son conversation for a young age (depending on the degree of exposure of the boy to technology, peers and the world) is pornography — which can be a lure for curious boys even before they enter puberty. A godly dad will train his son to build defenses against this corrosive addiction. (The everaccountable.com website offers a world of help on gaining and maintaining personal victory in this area.) Porn can set into a lifetime soul-assaulting temptation that cheapens the perception of God-given sexuality and impairs the ability to have a pure, life-giving one-man / one-woman marital relationship when God opens that door.
A key thing to understand about pornography habits is that the addiction is a symptom of a deeper cause, often a poor self-image, fear and insecurity that may often be springing from a poor relationship with Dad. Any child's self-image is shaped more by the child's relationship with their father than that with the mother (she is generally the heartbeat of the home, but he is the moral compass). Dad can strengthen his son's response to the mutual temptations of masturbation and pornography ("every man's battle" — you can search for that phrase online to find many resources for waging it) by his example and by the openness and sensitivity of his presence as the godly Abba (Hebrew word for Daddy).
