Little Tony (movie, 1998)

Brand, an unemployed illiterate in his fourties, lives with his wife Keet in some desolate corner of the Dutch countryside. Keet, being tired of having to read the subtitles on television out loud so Brand can understand what's going on, one day decides he should learn to read for himself. She hires Lena, an attractive woman in her thirties, to do the teaching. Lena and Brand develop a passionate relationship, and Keet decides to let it happen because she wants her husband to be happy. She even goes so far as to claim she never actually was married to Brand: it all was just a game, she's just his sister. Lena then moves in, and soon takes over. But after a while she gets pregnant and bears a son, Kleine Teun ("Little Teun"). Then Keet, who can't have children herself, finally caves in and decides Lena has to be eliminated ...