Two Queens and One Consort (1981) on Netflix

At the deathbed of his used-to-be militant mother an older man looks back at his childhood, when he was in love with his sensual aunt Coleta.

Returning to his hometown by the sea, Levien visits his unyielding mother (Kitty Courbois) on her deathbed. He looks back on his childhood (played by Eric Clerckx) when he was in love with his sensual aunt Coleta (Linda van Dijck) and his anarchist mother who regularly put the whole family in trouble.