Honesty and openness is the best way to go....My wife and I share everything, bank accounts, credit cards, etc. If she cared how much I spent, she could easily go and find out. I don't really care what she spends either as I know she has discretion just like me. Hell, when I was on my last hunting trip, she accidentally bought a $500 bottle of wine at a restaurant with her nephew and his wife in SC. Had she not told me about it, I would have never known.