The Vertical Ray of the Sun (At the Height of Summer)

The plot centres around three sisters, two of whom are happily married (or so it appears). The youngest sister is single and living with her cute older brother, whom she is desperately in love with. A second sister is married to a man who has another woman and child elsewhere whom he loves just as much as his wife -with a few conditions, she agrees to carry on with the marriage. The third sister and her husband are overjoyed to discover she is pregnant, and though he is tempted, her husband remains loyal to her.