I have anal sex with my wife, but I do not ejaculate. Now she is not my wife and I must marry her again. I know I did a bad thing but it just happened. What do I do now?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. Know that having sex with a woman in her anus is a great sin and an ugly act. Its perpetrator is cursed by the Messenger of Allah (Sallallahu Alaihi wa Sallam). Ahmad , Abu Dawood and others reported on the authority of Abu Hurairah (Radiya Allahu Anhu) that the Prophet (Sallallahu Alaihi wa Sallam) said, "Accursed is the man who has intercourse with his wife in her anus" . You should therefore make a sincere repentance from this sin. A sincere repentance entails three things: 1. To regret that you committed the sin. 2. To abandon the sin straight away. 3. To determine not to go back to it again. As for the assumption that this act implies divorce, that is absolutely incorrect. You should therefore, keep your wife. Allah knows best.