Story of infidelity and living arrangements

[Enderisme]

Looked everywhere and still can’t locate this story.
Basic outline: wife is unfaithful (maybe a one night stand) gets pregnant. Husband says marriage is over but wife is allowed to live at the house until the baby is born. Husband begins dating and wife watches and also slowly expands her sexually boundaries for her husband. She is obedient to him as a condition of living in the house.
Thanks for any and all help!