What kind of idiotic, ideologically-driven poor excuse of a father acts like this? He should have shown his son support while explaining to him the dangers of gambling. He should have given his son to understand that this win was a rare 1-in-lifetime event. So that the kid would not end up chasing his gambling win from his past days.
It becomes the father's loss if the son decides to keep the money he has won, and that is the most likely decision that he would take. The father who would have had some share of the money will now be left out of it when the son decides to keep it and that will also come in-between their father and son relationship. The father will say his son disobeyed him. If it is the Man's principle not to gamble, he should know that his son is not like him. He can tell his son that he wants nothing from the money, not wanting the Son who will be a man soon to return the money.