One of my favourite blues CDs include tunes from the first half of the 20th century. They’re sung by big-voiced women and mostly about lyin’, cheatin’, no- good men. In one song, the singer vows to cut her man “wide and deep” if she catches up to him.

I was playing the CD recently when I realized that while the theme of the songs was infidelity, it wasn’t always about another woman, but rather money. “You took my money and you run, run, run/I’m gonna hunt ya down and you’ll be done, done done.”

Financial infidelity is as old as the other kind. And often, like the other kind, it starts relatively innocently — a small lie about a purchase or a deflection about a debt. At its worst, as television producer Carol Ross Joynt writes about in her 2011 book Innocent Spouse, one partner has a completely secret financial life. After her successful and wealthy restaurateur husband died suddenly of pneumonia, she discovered he owed $3 million to the IRS.

Most financial infidelity doesn’t have such monumental consequences but if you are the victim, uncovering unpaid bills or a hidden cache of cash can slice through a relationship as effectively as an affair.

More than 23,000 people responded to recent survey by Today.com and Self.com revealing that 37 per cent of men and 56 per cent of women have lied to their partner about money.

A similar survey conducted in 2009 by Credit Canada Debt Solutions for Credit Education Week Canada indicated that there is considerable lyin’ and cheatin’ going on between partners about money.

To prevent your relationship from foundering on the rocks of financial infidelity, here are a few basic rules to follow:

1.  Each person should have some ‘fun money’ completely separate from the household accounts.

2.  Even after making a stupid purchase, reveal the true price to your partner.

3.  If conflict over money is longstanding in your relationship, consider marital counselling to get to the heart of the problem.

4.  If you are feeling victimized financially, ask yourself if you are actually enabling the other person.

5.  If you are hiding money because you don’t trust your partner’s financial management skills, try credit counselling through a reputable organization such as Credit Canada Debt Solutions (creditcanada.com.)

Is ignorance really bliss?

A look at who’s spending and telling in relationships:

28%. Check with their spouse on every single purchase

6%. Never tell their spouse what they spend on anything. (April 2012, Today.com/Self.com survey)