In-laws broke but have ton of equity they dont want to use

[Steve A.]

Strange situation.

In-laws have a home in Santa Barbara worth about $900K.  They have a $300K interest only loan.  They can no longer afford the payments.

My wife and I recently came into money.  I was planning to put that money to work in real estate- flipping, rentals, etc.  They found out we have money and are demanding we pay their mortgage payments.  

I told them it was great news that they had so much equity in the house, their retirement is covered.  Sell the house and buy something smaller, live debt free.  They don't want to do that-- they want to live in the house until they die and want me to pay for it.

I don't want to pay money into an interest only loan.  I don't want to be land-lord for family.  I don't want to gift them $300,000.  In essence, I don't want to put money into something that has a ton of emotion tied to it and there is no way to get that money out for an unknown amount of time, likely measured in decades.

Do reverse mortgages make sense?

If you were in this situation what would you do?