These lies often lead to a serious breakdown the relationship, so what are the most common ways of hiding financial difficulties?

Hiding credit card statements – One of the easiest ways to spend money undetected is to charge it
Concealing gambling winnings or losses – Gambling is a very expensive pastime
Understating spending – Some financial lies are more like half-truths
Secret bank accounts – Opening a secret bank account is often done with good intentions
Secret credit cards – Keeping credit cards a secret is surprisingly common

These are just clues to show that something is going wrong, the sooner the problem comes to light the better off all parties will be.

Source [Invest Money Stocks]