Money is said to be the root of all evil.  Cliche as it is, but it is real even in marriage.  Financial issues may be common to almost everyone, but it is relatively harder for couples.   Money habits expose our personality differences and values.  Your spouse may have a different way of handling money which can result to some dispute or complications when it clashes with yours.  In this way, money has the power to ruin a relationship. 

To avoid these financial complications, one of the most important key is honesty.  Make financial decisions together and be completely open and honest. Do not make any investment or go shopping without the other knowing about it.