Employ a few different tactics:
1- Delivery to work or mates address, its an oldie but it works (move it to the garage when she’s not looking/out/at night)
2- Use credit card in my name only, not joint account and pay it off in smaller chunks so she doesn’t notice (She only looks at the online banking once or twice a month, never looks at a full statement and would only notice big amounts going out in one go, a fraudsters dream)…
3- Operate a “One in one out” policy, or at least claim to, I have a knackered old frame on standby which I will claim I’m selling in order to fund the next big spend item, as it’s all just bit’s of metal to her, one large box being posted and a similar sized one coming back must equate to a “Cost neutral” acquisition…
4- Ask permission, sounds stupid but if you put it just right, using phrases like “I thought I’d make sure you were OK with it” and “Only if you think we can afford it” basically make her think you factor her thoughts and opinions into your decision making processes (of course you’re not, you’ve probably already clicked “Go to checkout”), she’s more inclined to agree and therefore can’t bollock you, when a big box arrives and you get the “what have you bought now?” line you can respond with “it’s that Frame/Fork/Wheel I asked you about last week, I did tell you….” Normally good for at least 3 purchases until she works out you’ve bought several things on a one item “Permission slip”…
My missus never goes near the garage, she probably spends more than me on Clothes, Bags, Jewelry or any other crap she buys and then never wears/uses, But I never point this fact out, she knows it I know it, but making the point would be almost guaranteed to turn her into an arsey nightmare for a month, plus my expenditure has been pretty minimal the last 24months or so and what I have spent on has mostly been riding Clothes rather than parts…
It all sounds terrible doesn’t it, the lying and sneaking about just so you can own some shiny bicycle parts…