The Sweet Sounds of Life(1999)

Original title: Il dolce rumore della vita

Sofia, a budding young theater actress, unwittingly discovers that Bruno, her beloved acting teacher, is gay. Heartbroken and determined to flee as far away from him as possible, she meets a young girl on the train who gives birth and abandons the baby. Sofia makes a life-changing decision: she takes the child and passes him off as her own son, naming him Bruno.