Not the normal type of hoarding mind.
When I was I in my first marriage I was saving up for a new bit of tooling for my workshop (employed, make items for sale on side). This was expensive, so I decided to start saving by stashing 10-20 pounds a week. This i did from my money not family money, as we had a joint account but also retained our own accounts for the little bit that was left over.
I went without for a couple of years, almost got to my target amount, then my partner had an affair. Lots of drama ensued but we limped on, trying to survive for another two years. Now my wife didn't know of my fund and after the affair I decided go keep going with it, really going without now to save more, but being careful to keep it within bounds of normal spending, so I scraped up to about 25-30 a week.
Relationship ended, no DC thankfully, divorce and the split left me with not too much. Luckily for me, I had an untraceable 3.5k in my back pocket, which let me rent a room, get back on my feet, reestablish etc.
Anyway, I am into another relationship now, creeping towards marriage and I am thinking of starting a 'just in case' fund again, which I could realistically fund with about 25 pounds a week without it looking excessive on statements. Is it wrong to do this? I love my new partner, want to marry but I have been burnt before and know that the little bit I had saved my bacon.
Please no 'all money is family money' diatribe. Its not how I do it or my partner wants to do it. Vast majority goes into joint account, but the remaining few hundred after house/bills/food/any DC remains with the person. I shudder to think how much worse it would have been if we had both had everything in one joint account.