Sunan Ibn Majah, Volume 3, Book 9, Hadith 1923 (DarusSalam) ⓘ
It was narrated from Abu Hurairah: that the Prophet said: “Allah will not look at a man who has intercourse with his wife in her buttocks.”
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ الْمَلِكِ بْنِ أَبِي الشَّوَارِبِ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ الْمُخْتَارِ، عَنْ سُهَيْلِ بْنِ أَبِي صَالِحٍ، عَنِ الْحَارِثِ بْنِ مُخَلَّدٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ ـ صلى الله عليه وسلم ـ قَالَ " لاَ يَنْظُرُ اللَّهُ إِلَى رَجُلٍ جَامَعَ امْرَأَتَهُ فِي دُبُرِهَا " .
also referenced under: Hadith 1923 (Reference) & Book 9, Hadith 1998 (In-Book)