Mein Schüler, seine Mutter & ich (2008)

Music teacher Carlo, an easygoing old rock'n'roller, meets doctor Ellen in hospital. She is completely stressed out, so that even son Franz often falls by the wayside. A short time later, Carlo makes an unforgivable mistake: fed up with the pupils' never-ending paltry questions, he advises Franz, whose anger at his mother is slowly boiling over, that he should simply report her to the Youth Welfare Office.

Unfortunately the movie Mein Schüler, seine Mutter & ich is not yet available on HBO Max.