What is a short summary of the story, Retrospective, from the collection, The UnAmericans?

In the story, Retrospective, recently separated Boaz struggles to understand why his estranged (and newly pregnant) wife Mira left their relationship, and also to reconnect with her. The possibility of that reconnection seems to disappear when he discovers both the truth behind her choice and the fact that her beloved grandmother made a similar choice – although in her case, her husband put up with the situation in a way that, narration suggests, Boaz is unable to.