Abu al-Juwayriyah said: A man asked Sayyiduna Ali (may Allah be pleased with him) about that, and he said: You have sunk to baseness, may Allah debase you! Have you not heard Allah Almighty say: "Do you commit an indecency such as no one in the worlds has committed before you?" [Surah al-A'raf: 80]
(b) Abu al-Mu'tamir said: While Sayyiduna Ali (may Allah be pleased with him) was on the pulpit, he was asked about having intercourse with women in their backsides.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14127