Money is one of the biggest topics couples argue about. Whether you want to buy an expensive toy (for your kid or yourself) without having to clear it with your partner or have debt you’re embarrassed of and don’t want to discuss, it is often tempting to hide financial information to avoid a fight. Let’s be very clear here: This is considered “financial infidelity” and it can be just as bad, if not worse, than cheating. Small lies about money can balloon into big ones, and big ones are the stuff that jeopardizes marriages — and lead to resentment long after a divorce. Lies about cash can be just as bad as lies about cheating, but they carry the extra sting of taking a toll on your partner’s bank account.