I have a very similar story that happened to my great grandpa.
His wife died and then he buried her. Back then, in my country, they would dig a hole and place a large flat stone on top of the hole. When he finished everything (digging the hole and all), he was ready to leave and before he turned around, a voice from within the grave said:
“You’re going to leave me in here, love?”
My great grandpa, being the badass man he used to be, responded:
“I saw you die in my arms. Whatever the fuck you are, yes. I’m leaving you in there”
He heard a hysterical demonic laugh as he walked away from his wife’s grave.