Is going out with a former female colleague to a public cafe considered reprehensible (makruh) or forbidden (haram)? And does it entail sin, even if the intentions are good and nothing happened?

Friendship between a non-mahram man and woman is a cause for fitna (temptation leading to sin) and corruption, and Islamic law prohibits every means that leads to the unlawful. Therefore, one must repent and sever the relationship. Their sitting together and exchanging conversations and affection is not permissible, in order to close the door to fitna and evil. The esteemed scholar Al-Khadimi said: "It is not permissible to speak with a young non-mahram woman without necessity, because it is a place of fitna."