The Ruling on Having Anal Sex With a Wife
Question:
A man asked his wife to have sex with her in her anus, is this action correct from the religious point of view?
Answer:
This deed is forbidden, for it is reported by Abu Dawud and others that the Prophet (sallallaahu alaihi wa sallam) said: Cursed is the one who has sex with his wife in her anus.
Source:
Shaykh `Abdul-`Azeez Bin Baz
Fatawa Islamiyah Vol. 5 Page 444