Question about ethics/morals regarding business partners?

I've recently partnered with a locally owned business helping the owner sell trading cards online. I earn a 10% commission, and he wants my commission to be removed from the cash flow. However, I want to reinvest the money in the venture. I realize he's concerned both with the money getting mixed up and not knowing who paid for what, as well as my investments undercutting his product acquisition and profits. However, I'm keeping an incredibly detailed record of purchases and sales, and I was planning on alternating every 50$ invested in product purchased between his money and mine, thus preventing any unfair growth. Would it be considered overly sly and/or poor taste to go through with this plan without his consent? I'm 100% sure I could move forward and prevent any potential issues such as confusion towards ownership, unfair/unequal profits etc. The only realistic consequence would be him getting upset at the fact that it's happening, should it come to light(which i'm sure it eventually would, given the nature of the business). He's a very stubborn man, and I highly value the partnership and potential for growth, however I feel like what I do with my money should be my business. That being said, I'm conflicted because I understand his concerns, and all of the initial investment/product was his. Any advice/insight?