Maybe they are hiding it because they know their family doesn't agree with it?
We know that many of us are in this situation, the family doesn't know about your gambling because you know that they will be angry with you. I can say this because I also know someone, because he is so addicted to gambling, he even used his family's money and he bet on his car just to get back what he lost. Of course his wife was so angry with him and he kicked him out and even his children were also angry with what he did.
Don't destroy your family just for a gambling hobby because it's not worth it. If that kind of hobby is not okay with your family, there are many others out there. If you are also having trouble stopping and that you are addicted, you can tell your family so they can help you. You have a family you can reach out to, you are not alone. Just tell them your problem so they can support you.
If you pay your bills and don't depend on anyone, why hide it, now you do live with your parents, no way, it's common sense.
In the case you name there is no discussion, he is an addict, he is not a healthy person, anyone who puts money at risk that does not belong to him is a thief or addict, it is that simple.
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