This short story can be found in George R.R. Martin's Songs of Love and Death, an anthology of short stories by modern masters.
I LOVED this story. It is the story of Jerry and Dolly MacKenzie, Roger's parents who are briefly mentioned in the Outlander series. This story is apparently referenced in An Echo in the Bone. I have not yet listened to this Outlander book because I am waiting for Susan to finish A Breath of Snow and Ashes...but I'm not sure how much longer I can wait after reading this short story!