There's a reason 'friendly' financial advice is free

Despite having the best intentions, giving advice doesn't always go the way you planned. Especially if it's telling your sister to how to invest her 401(k), only to find out your sage advice caused her to lose 25% of her retirement fund.

It's a fine line you must tread when deciding whether you should pipe up with financial advice or just keep you mouth shut and nod sympathetically.

Experts say there are a few instances when your course of action is clear: if a person is in danger from financially self destructing (gambling away their savings, spending compulsively, etc.) then you should speak up, no matter what.

However, relationship expert Susan Newman says general advice giving, about how much to save, where to bank or how to trim a budget, can lead you down a slippery slope. "Even good advice can injure or ruin a relationship because it might not be right for the recipient," Newman said. It also might not be wanted.