A man should not stay with a woman in seclusion
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنْ يَزِيدَ بْنِ أَبِي حَبِيبٍ، عَنْ أَبِي الْخَيْرِ، عَنْ عُقْبَةَ بْنِ عَامِرٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِيَّاكُمْ وَالدُّخُولَ عَلَى النِّسَاءِ ". فَقَالَ رَجُلٌ مِنَ الأَنْصَارِ يَا رَسُولَ اللَّهِ أَفَرَأَيْتَ الْحَمْوَ. قَالَ " الْحَمْوُ الْمَوْتُ ".
Narrated `Uqba bin 'Amir: Allah's Messenger (ﷺ) said, "Beware of entering upon the ladies." A man from the Ansar said, "Allah's Apostle! What about Al-Hamu the in-laws of the wife (the brothers of her husband or his nephews etc.)?" The Prophet (ﷺ) replied: The in-laws of the wife are death itself.