In This Our Life by Ellen Glasgow, 1942

Asa is the long-suffering husband of Lavinia. He never loved her and is financially dependent on her wealthy uncle, William. Asa has two young daughters, Stanley and Roy (I never figured out why they have male names). Roy is married to Peter and Stanley is engaged to Craig. Stanley breaks her engagement with Peter and elopes with her sister's husband. Roy and Craig strike up a relationship and talk about getting married. Peter eventually commits suicide and Craig confesses he still loves Stanley but wants Roy to "rescue" him from her. All Asa wants is his daughters to be happy. He relates to and loves Roy to pieces unlike his feelings toward Stanley.

It's a story of the generational contrasts of the attitudes about marriage and the commitment to relationships. I found the plot drawn-out and repetitive. A middle-of-the-road Pulitzer.