Sisters of Charlie's Circle. Charlie’s Circle Series, #2

This is the second novel in the Charlie's Circle series.. In first novel 'Traveling Around, ' Charlie, a widower, hires Sandy, a young woman, who becomes his wife, to drive for him. At Thanksgiving, he runs onto Crystal, his old girlfriend who has become successful and wealthy. She invites them to her mansion in Houston, Texas. Sandy allows Crystal to become involved with Charlie since they have a daughter together.
To keep Charlie from traveling, Crystal offers to put his wife Sandy through college. Charlie wants to live in Arizona, so they get ready to move there where she will attend college. The second novel 'Sisters of Charlie's Circle' picks up as they are moving to Arizona, so Sandy can attend college. The three of them move into an expensive home in Tucson, and Sandy starts college. Crystal hires Lois to cook and clean for them, but her husband leaves her, so she gets involved with Charlie too.  To help the women get along, Charlie invents Charlie's Circle, so the women will support each other and get along better.  Crystal leaves Charlie since she doesn't want to share him with the other women but soon regrets her action.  She moves back to Arizona and buys a large ranch and gets Charlie and the other women to move onto her ranch.
Crystal rejoins The Sisters of Charlie's Circle and eventually the members allow another woman into the Circle. Due to a change in Arizona law, plural marriages become legal, so Charlie marries all the Sisters of Charlie's Circle.  As this novel ends, he recalls his dying wife telling him that there will be a fifth wife. This novel has explicit love scenes so is only suitable for mature audiences.