~snip~ If really he has been gambling irresponsibly, there is going to be a time that the money he is using to cover up well be long gone and will be broke in the future.
I firmly believe that people who are addicted to gambling will eventually stop, because they will most likely go bankrupt one day when their debts get bigger and they can't pay the money back. Another impact of gambling irresponsibly is the destruction of family relationships, friendships and other relationships because usually people who are addicted to gambling will be in debt to anyone they know and most likely will not be able to pay it back, so in the end they will be shunned by them.
In many cases, gambling addicts end their lives because they are unable to face the mounting debts. I don't want it to end like this, so as long as we can control playing patterns and manage finances, do it. It's better to prevent becoming a gambling addict before it ends badly.