I love this thread, and the intriguing idea! However, DH and I have separate finances (always have). We do go halves on mutual purchases, such as new appliances, home improvements, vet bills, etc. We also each have our own savings (retirement, emergency funds, etc.)--but have agreed that, in case of emergency, we'll tap into them for each other. To make a long story short, I can spend my money as I choose, and so can he, so I don't need to hide anything from him with the jewelry! However, I don't always show him my purchases (especially if I had recently lectured him about saving money more

). I am a bit of a shopaholic with the jewelry (I have no other hobbies, and spend little on other things, to be fair), but I always have made sure that my retirements and saving funds come FIRST, out of my paycheck. What's left over after the bills are paid is mine to play with. Heck, I get the stuff dirt cheap anyway...
All that said, when I buy that mythical bling-bling ruby, diamond and 18kt necklace I lust after, I may NOT tell him!