She had been up in the mountains camping when human race, as it so often does, died out. The cause of extinction was nothing especially fantastic, no aliens, no zombies, no hubris, just a simple flu. She drove down from the mountains relaxed and cheerful after several months, being a land-lover and having a trust fund. The towns weren't entirely deserted. At a certain point nobody had bothered picking up the bodies. It was immediately obvious that nobody was alive there, but she drove around looting and searching for survivors until her truck ran out of gas, at which point she picked out a house, and adopted one of the dogs that was still tame.

So she lived alone as the forest came to her, taking provisions from the land and eating the last of what civilization had given her, with no intention to restock once that ran out. She had a garden going to pass the time, kept her own house clean while the others rotted, and took up sculpting so it seemed like there were people still around.  The flu never got her. A doctor could have told her why but there were no doctors.

He came along the crumbling concrete one day and saw her. He had a horse-drawn wagon from a museum, which he restocked whenever needed in the towns, avoiding the skeletons which grew more and more strewn about. He could take care of his horses, but he never had much of a love of the land. He lived off the fat of mankind.

She was in her garden singing but broke off to look at him. After they had looked at each other for a long time, she said, in a voice used to talking to itself, “so I guess we should restart humanity?”

“I'm gay,” he said.

“So am I,” she said.

And since he was a nomad and she was a farmer, that was the end of that.