"Mention was made in the presence of the Messenger of Allah of some people who did not like to face towards the Qiblah with their private parts. He said: 'I think that they do that. Turn my seat (in the toilet) to face the Qiblah.'" (Da'if) Another chain with similar wording.
ذُكِرَ عِنْدَ رَسُولِ اللَّهِ ﷺ قَوْمٌ يَكْرَهُونَ أَنْ يَسْتَقْبِلُوا بِفُرُوجِهِمُ الْقِبْلَةَ فَقَالَ أُرَاهُمْ قَدْ فَعَلُوهَا اسْتَقْبِلُوا بِمَقْعَدَتِي الْقِبْلَةَ قَالَ أَبُو الْحَسَنِ الْقَطَّانُ حَدَّثَنَا يَحْيَى بْنُ عُبَيْدٍ حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ الْمُغِيرَةِ عَنْ خَالِدٍ الْحَذَّاءِ عَنْ خَالِدِ بْنِ أَبِي الصَّلْتِ مِثْلَهُ