I don't tell my wife about every gun I buy but she knows I spend some spare overtime money on them. Likewise I don't question her buying either. Now when we were younger and money tighter we didn't do such things and I didn't buy many guns either. During those times we discussed my rare gun buy and I used the layaway plan mostly.
We both share the gun safe as she keeps valuables there and knows what I have. I suppose I could check out what she has there to if I had a mind to.
We also have seperate and joint bank accounts for simplicity but give each other access to all. She can check my gun account anytime she wants and would currently see it's $34.00.
We both get UPS shipments too and sometimes she'll ask about a heavy one and I'll tell her it's ammo. She'll tell me to be careful lifting it. Other times I'll tell her they are gun parts and she's good with that too.
I built three ARs and was getting quite a few packages for a while there. She asked what they were all about about and I told her. She did say that's a lot and be careful of your spending.