Sayyiduna Khuzaymah bin Thabit (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings of Allah be upon him) said: "It is forbidden to have unnatural intercourse with women (that is, to use them from the rear)."
Hadith Referenceسلسله احاديث صحيحه / الزواج ، والعدل بين الزوجات وتربية الاولاد والعدل بينهم وتحسين اسمائهم / 1469