I think you were wrong to put him on your account without his agreeing to that. But that's in the past now. Do keep your business as your business. If the two of you were to get serious with the potential of being partners in life, then he would have every right in the world to want to know your financial situation. If that potential doesn't exist, then I kind of wonder what the two of you are doing after six years. He has no business praying into what you do on forums like this, so don't discuss it with him. He'll just get inappropriately curious.

With a guy like him, you may have to put out an extra effort to keep your boundaries and be your own person. If this credit card thing is the biggest issue you've had, then I don't think it's all that big a deal.