Thanks for you replies
More opinions are welcomed.
AlwaysGrowing: In the story the two women mostly live together as the man travels (and always has) a lot. So maybe they've found a way to deal with noises on those occasions he's home.
Thanks SchrodingersCat. I also came across a mention of such situation in another thread today, but I'm not sure if it's different people. So maybe I'll go with it and write the story in a way that makes it clear there's nothing morally (or legally) wrong happening
Always up for a challenge \o/ Anyway, I need to spend a couple of more days thinking about these characters, so there's still time to add your two cents.