A woman saw her husband having sex with another woman. She saw with her own eyes . Is she considered automatically divorced from the man or she is still his wife ?Jazaaka allahu kheyran.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The marriage is not annulled if the husband commits adultery, as this does not affect the continuation of the marital bond. A woman's divorce occurs only if her husband utters the divorce or that the Islamic judge rules on it; otherwise, the principle is the continuity of the marriage.

We warn that this woman must refrain from spreading the matter of her husband's adultery, as this leads to slander, and she deserves the Hadd (the corporal punishment determined by the Islamic Sharee‘ah) if she does not prove her claim by providing four witnesses. Allah Says (what means) said: {And those who accuse chaste women and then do not produce four witnesses, lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient.} [Quran 24:4]

She should advise her husband and remind him of Allah The Almighty and the seriousness of this immorality and call him to repent.

Allah knows best.