Is it permissible for men and women to mix at the dining table or elsewhere, especially the husband’s brother and the wife’s sister?

The questioner : Is it permissible for men and women to mix at the dining table or elsewhere, especially the husband’s brother and the wife’s sister?

The Shaykh : It is not permissible, my brother, because today’s upbringing is not Islamic upbringing. It might have been said that such an incidental matter is permissible if there were Islamic upbringing. For example, the wife would be in front of her husband’s brother, appearing in proper Islamic clothing and with her natural face, not reddened, not adorned, not wearing makeup, and nothing else. Then she would maintain proper conduct in her speech; if she spoke, there would be no smiling, no laughing, and certainly no winking. But does this exist in our current upbringing? The answer is that it does not exist. Therefore, we say it is not permissible.