Looking for a story where a brother-in-law seduces the wife

Hi,

I am looking for a story where the brother-in-law seduces the wife. He moves in, has a job in a supermarket with different shifts, with plenty of time to seduce his sister-in-law. He realizes that his sister-in-law is busy with his nephew, and so in order to get her affection and attention, he takes him out to park and play with him. These are the details I remember. This is most likely a recent story. If anyone can please find it for me, I would really appreciate. I have been trying for the past half an hour with various keywords but to no avail.