Help find a story

[rearden_steel_2]

I read a story in the last 6 months or a year tops. I'm pretty sure it was Incest category. The guy was having sex with his sister when his parents came home. He pretty much disappeared after that embarassing, home destroying moment. Years later , maybe at the death of his father, he is reunited with her. Both are married I think and both spouses are cheating on them. So he resumes the relationship with his sister. Based on some idioms in the story I think it was written by a British person.

Thought I favorited this story but can't find it now. Please help. Thanks.