The Finnster 2010 one on netflix

Finn (15) is an uncomplicated schoolboy until one day, coming home from school, he catches his father Roelof in his moms dress. The man Finn has looked up to his whole life, wants to become a woman. Finn, just discovering his own sexuality, is troubled by this new discovery. A struggle with feelings of shame, love and loyalty follows. Luckily Lizzie, his newfound friend, is there to help him.