@Sammy Lyon that is correct, the bank loaned 80% of the purchase price and the seller essentially deferred receiving the other 20% of the sale (his equity in the property) because he became the bank for the other 20%. So I paid the 2nd mortgage note "to him" is the answer to your question.
I made monthly mortgage payments directly to my seller who no longer owned the property, but held a 2nd position mortgage and promissory note just as the bank held a 1st position mortgage and note. It's a lot riskier for the 2nd position because if I quit paying the bank and the bank foreclosed, the seller in 2nd position would not stand as good a chance of recouping that money.
I also signed a personal guarantee to both the bank and the seller since I purchased in an LLC. The important thing is that the seller has to have a lot of trust in you and faith in your ability and likelihood of repaying the debt. From my perspective, my name and reputation were on the line and at the end of the day if something went wrong and the bank foreclosed, I would have still done everything in my ability to make my "Private lender" whole and repay that debt.
This was another investor, so he approached it with an investor mentality. He was going to make 7% interest on his equity over the coming 5 years.
Another detail I left out is when I paid off this 2nd mortgage three years early, I made a proposition to the seller and successfully negotiated a discounted payoff. It amounted to about $1500 discount he was a little reluctant to agree to, but he obviously was ready to receive that lump sum. The lesson here is if you don't ask, then the answer is automatically NO.