Imam and Ma'mum

What do we do when we know that someone who is leading salah is in the habit of watching pornographic movies and looking at nude women, etc? Are we allowed to pray behind such a person who commits such grave sins?

Dear scholars of Islam, As-Salamu `alaykum. At work when the time of prayer comes, I pray in my office. I have a Muslim secretary and she wishes to join me in prayer. I have been telling her to pray by herself and that we cannot pray in jama`ah (congregation). Am I correct, because I heard that it’s not allowed to pray in jama`ah with one non-mahram woman only?

As-Salamu `alaykum. Can a woman lead other women in congregational prayer?

Alsalamalaykom, My question is regarding sujud 'prostration; when praying behind an imam in congregation, is it obligatory to arise from sujud as soon as the imam does, I sometimes continue praying in sujud and arise slightly after the imam does to make tashahud, is this acceptable? is the ruling different for obligatory prayers and voluntary ones such as taraweeh and tahagud qiyam or the same? how important is this issue?JazakumAllahu Khayran