This is a given -
Johnboy:
Undoubtedly he is masturbating whist wearing the stockings and suspenders.
and at his age and having started using such props, he will by now be a compulsive wanker. The agony aunt in saying leave him be with no confrontation is overlooking that his addiction to masturbation will get worse. This young man - really a boi - will lack the maturity, self-discipline and sense to control for himself what is in him a dirty habit, preventing him fulfilling himself as a sexual being.
For those reamisters, I think your suggestions seem a good thing Johnboy. At the least, some regulation of his masturbatory action must be accomplished and fitting a cock cage would have an immediate and big effect on the boi. His 'at home' attire should in future include his stockings and suspenders as a matter of routine I would say. Dressed like that, shaven and with his cage fitted, he would present a spectacle to visitors and perhaps part of disciplining him and adjusting him to his new, more natural for him life would require him to be present when his lady entertained friends and neighbours.
Your idea that his secret should be revealed to girls his own age is essential I think - so he may form a relationship suited to his interests and abilities with one of them. I would think though that any female should be made aware of his condition, even neighbourhood teens if they show interest. Most of them, if they think about him at all at the moment will assume he is a wanker so the extra information about him will be the only surprise.
He perhaps needs to make some friendships with other lads around his age. He could not expect that they would not know all about him too though. Perhaps his lady could consider having one or two young men stay at her home as lodgers - maybe offering accommodation to students. At the least her mister could then see up close how real men behave and no doubt discover what they think of wankers like him. Can't be avoided in the long run so it would be a good thing and help his adjustment from his secret life to openly admitting his state.