A new study says that one in five men and one in ten women have private stashes they don't reveal, averaging £2000 but sometimes a lot more.
They have all sorts of reasons for squirrelling it away. In case the relationship fails, because it's none of their partner's business, because it gives them some financial independence, and for men because a stash of cash makes them feel more masculine.
Those high-earning bankers in the City of London are said to be particularly prone to hiding large chunks of their earnings from their partners. It must be pretty easy, with such astronomical sums flying in all directions.
There's no way Jenny or I would have secret accounts. We've had joint accounts for many years and whatever's in them belongs quite clearly to both of us. When we first met I had my own bank account with quite a sizeable sum in it (which Jenny knew about) but we eventually pooled all our money.
I suppose if you genuinely think your relationship might collapse, then having some private savings is a sensible precaution, to enable you to start afresh. But I can't see any other good reason for salting away money your partner doesn't know about.
To me it suggests terrible deceit and lack of trust, keeping something very important from them because they might not approve. And if you're hiding something so significant, what else might you be hiding that they ought to know about? A taste for secrecy can spread into umpteen areas, like a virus, until deceit becomes routine.