Trying to find a story where the father in law has sex to give daughter in law a baby

[Omniferis]

I was reading a story a while back that had a husband and wife who couldn't have a baby, Then she came up with the idea of fucking her father in law, I got the middle where he is fucking his wife in the other room before going to her. I sufford a power outtage and it fride my computer. If anyone knows the name of the story or the author could you please help me? Thanks in addvance.