Do you check conscious or unconsciously lied to someone or to your love ones to cover your gambling loses? And what kind of lying did you do? Did you tell that you just lost like $50 but in reality it's $500.00? Or that you lend some money to your friend, but then you go and play on casinos? Or you tell that your paycheck is short and there is something wrong with it and so you will have to ask your company's HR about it?
I never lied to anyone, specifically for gambling matter. If I lose $500,000 I will say I have lost $500,000. 
By the way, lying about the amount of our losses, it means we never admit it. Admitting the losses is needed, because it is the way that we give a lesson to other people about the possible losses. And it reminds us to gamble in a proper way to avoid another big losses. However, it is lucky that I never experienced huge losses because I keep gambling with small amount of money and I never try breaks my limits. Once I spend my gambling funds allocated at that day, I will immediately stop it. Actually, it is not so difficult to avoid severe losses if we keep gambling properly.