How often the once romantically optimistic premise of unconditional honesty, openness and sharing deteriorates into subterfuge and covert daily exercises.

Don't do anything with credit cards. It's not necessary. Do it all in cash. Have separate funds for the hobby from your regular living expenses. Keep it in a separate bank account in your own name and in a separate compartment of your wallet.
Don't let your hobby spending take away needed funds for your necessities.

Just pocket cash here and there and stash at home somewhere as your kitty.

If you mess with bank accounts open one in your name online.  Set it up to not send paper statements or send statements to work.  Direct deposit in small amount of $.

Re:Financing the "Hobby" Anonymously (SO can't trace)

Here's what I do:

Everytime I go to the market, or to any store, I ask for $5 or $10 cash.  I put it in an envelope in my office.

If I get an expense check or bonus, I deposit it at the teller window, and get some cash back, rather than depositing it in a cash machine, and taking cash back.  That way, it shows as a deposit, but with no withdrawals.  I put the money in the envelope.

If you are thinking about financing providers on credit, you may be overextended.

I figure I can accumulate a visit every 2 or 3 months.  Frankly, that's all I need.

Kill the idea of financing hobbying with credit now before it destroy your finances and ultimately your life. Like anything else, if you cannot afford it save until you can.