'Allama Alauddin Haskafi wrote the following: Dayyus is the person who don't care about his wife or any other mahram women's indecent behaviour with other men'. (Durr-e-mukhtar, vol.6, pp. 113). My Master Ala Hazrat Rahmatullahi Ta'ala Alayh says: 'a dayyus is a severe and repulsive sinner (fasiq), and offering Salah behind a Fasiq-e-mu'lin (the one who commits sins flagrantly) is Makruh Tahrimi. Making him the Imam is not permissible, offering Salah behind him is a sin and anyone who has offered Salah led by him must repeat his Salah because it is wajib ul i'adah.' (Fatawa Razawiyyah referenced, vol.6, pp. 583). PS: 'if the man has made all possible attempt according to his status and fullfils all the requirements of preventing unveiling but they still dnt comply, then there is no blame on him and he is not a dayyus. plus whilst preventing one must make sure that they dont behave so strictly with their wife, mother or sister that it cause chaos in their house'.