Investment Property Down Payment Financing with Business Partner

[Glenn McCullough]

Similar questions have been asked on this forum before, but I'm still not clear on the correct path forward. My situation is currently the following: 

-My business partner, Jon, and I are looking to purchase our second investment property. For our first property, I fully funded the down payment with the bank, we formed an LLC, I transferred the title of the home to the LLC, and Jon purchased 50% of the LLC by way of paying me 50% of the down payment for the home. All of the revenue / costs for the LLC (property) since then have been split 50/50.

-In terms of the second property, Jon is looking to fund the down payment this time around. The issue here is that Jon doesn't have the full amount of funds necessary to pay for the entire down payment without dipping into other investments, which he'd like to avoid. Jon thus wants me to pay him 50% of the closing costs upfront for him to secure the down payment of the house before going through the same steps as our first property (LLC formation, transferring title, etc).

My question would thus be how should I provide Jon with 50% of the funds upfront completely by the book without incurring financial / tax penalties or getting flagged by the IRS?  Or is there no appropriate way to do this, and we should look to have one of us fully fund the down payment similar to the method used for our first property?  

Thanks for the help in advance!