He lit her on fire first, and watched with calm detachment the full extent of his emotions while she burned. As she crackled to ash, he kept waiting for a feeling to strike him with the full import of what he was doing. None did. He neither lamented nor enjoyed what he saw. She was there, and then she was not, and the transformation smelled.
That's that, he thought. When all is said and done, everything goes back to dust. There's no connection beyond sharing the same space at the same time.
Then it was time for the house. Then the dog. Then her parents, still smiling stupidly as though their good will made any difference. They were okay folks, really. But that didn't change anything.
When the sink was full of picture ash, he signed the papers, packed his clothes, and moved out.