Burnt Offerings (1976)

[stink_mikenzie]

 

If It's Too Good To Be True, Don't Trust The Creepy Adult Siblings
In this sun bleached scream, a family scores the deal of a lifetime on a summer rental house with one catch: the 85 year old mother of the homeowners will also be staying all summer and our family just needs to bring her three meals a day. Hesitant at first, the husband Ben agrees to go so long as Marion, the wife, agrees to be Mother's caretaker. 

What follows is a sweat soaked spiral of malice as Marion and the house develop a...special relationship. This movie predates The Shining and it's easy to see how King could have been inspired. It can be a bit long in the tooth at nearly 2 hours but I definitely recommend if you're in the mood for some horror in broad daylight.