Is the questioner sinful for failing to advise a woman who patted him on the shoulder, and if his colleagues approach him while he is seated, should he stand up, and what should he say to them if he wishes to advise them, knowing that this matter is widespread in the company and is not considered among the forbidden things?

The mixing of men and women at work is forbidden, and a Muslim must avoid it, as it is a gateway to tribulation and corruption. Therefore, it is not permissible for a Muslim to work in a place where there is mixing, even if he himself does not mix, because a Muslim is required to change evil. If he cannot change it, then he must leave that place, especially if he does not possess strong faith to denounce the evil. As for one who keeps silent about evil and approves of it, it is not permissible for him to work in such places, and he incurs sin.