Using a private lender as a debt partner for down payment - how it affects mortgage

Hi Everyone!

I am a multifamily and SFH investor. I am partnering with a private investor who is coming in as a debt partner to cover the down payment. This is my first time structuring a deal this way and wondering how a bank will view that since the private lender won't be on the mortgage or the title. Lookiong for advance and appreciate any feedback. Thank you!

Best,

Matt Smith