We Are Together, Mom(1976)

Original title: Мы вместе, мама

After serving in the army, Maxim came to work as a driver on the construction of a seaport. There he met and befriended little Pasha, the son of Galina, an accountant who is about to get married. But Pasha doesn't like his mother's suitor, and the boy hopes that she will pay attention to the kind and cheerful Maxim.