Who is This? and Lovers' Quarrel - Sister Stories?
Since I already can only "comment" here, I will take the time to read the story in full.
Full disclosure what I'm about say I'm not saying because of our kinship or that I would favor you as a writer. In Who's This? you made a point about the husband cheating around in the belief he's not found out. The wife knew he had a lover but nothing about who she was.
In Halhow's story, the third woman is sent away by the second and the first was only short about meeting the second in person, but she knew a lot about her starting with knowing they shared a woman.
You both write about a premise that comes about from two different situations, and are being handled in two different ways. Having said that his story is plenty interesting, and at best are cousins (not even kissing cousins) not siblings.
Life is like a boxing chocolate, you never know what you'll get, except for the hook.
It's interesting as I don't see them as that similar. For me the protagonists in Who Is This are more likeable and real. The challenge is more spontaneous. One of the women is morally superior to the other. As well as lust they also show fondness for David. The discussion in phone and on person is more normal for want of a better word - almost like frenemies or gfs. Also the contest is hand to hand and no toy / weapon. In addition the melancholy air and phyrric victory tone of Who Is This make it a very different tale - not as much hate between the fighters.