If I understand this correctly, let's say the LLC plans to buy a property for $100k, with you & your partner holding 50-50 share ownership. Your partner puts in $75k & you put in $25k. If I were your partner, I'd want your ownership share reduced by the amount of your outstanding note as collateral in the event that you default. So, the note needs to be inside the LLC.
What does the LLC plan to do about operating expenses?