The Third Wife by Lisa Jewell

Adrian is in mourning for his wife, Maya, who recently died. Maya was his third wife, and he has great relationships with his two previous wives and his five children from those marriages. In fact, they all acted like one big happy family, even going on vacations together. However, Adrian finds out that someone was secretly sending horrible messages to Maya before she died, saying that the family hated her and wanted her gone. Did the messages come from someone in the family or a person close to them? In The Third Wife, the reader follows Adrian on his journey to discover the truth--and learns the reasons he finds himself  thrice-married and now alone. This Lisa Jewell book from a few years ago is more relationship-focused than her most recent books of psychological suspense.