Who is the father in a love triangle

Catherine previously served as the chief editor of a fashion magazine. After marrying the prominent businessman Stephen, she chose to leave her career and focus on family life. Over the years of their marriage, Catherine diligently fulfilled the role of a devoted wife. On her birthday, she dressed meticulously and enjoyed an intimate evening with her husband. However, she later discovered photographs of Stephen in compromising situations with his secretary, which deeply hurt and angered her. In response, she sought solace at her close friend Amy's home, where she indulged in alcohol to ease her distress. Unexpectedly, during this time, she became involved with Amy's son, Alan. It was revealed that Alan had harbored feelings for Catherine since he was 13 years old. A month later, Catherine realized she was pregnant. Given the proximity of her intimate encounters with both Stephen and Alan, she was uncertain about the identity of the father. At this moment, Stephen, who had been absent for a month, suddenly returned home.