His Friend’s Wife Got Married to a Non-Muslim Man While She Is Still Married to Him
26-9-2021 | IslamWeb
Question:
SalaamOne of my friend's wife did a heinous sin of getting married to a non muslim man secretly using their traditional method without divorcing him in the first place. I am assuming that this marriage is not valid. My friend forgave her and kept her in marriage. However recently they had a fight and he said to her ''You got married to so and so"" or "You are married to him""...If my friend said these lines without intending to divorce her, do the uttering of these words constitute divorce.
Answer:
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.
If the situation is as you mentioned, then your friend’s wife has committed a grave major sin in two respects:
The first: The fact that she is currently married, and a married woman is not allowed to marry another man until he divorces her and her waiting period from him expires. Allah Says when mentioning the women that are forbidden to marry (what means): {And [also prohibited to you are all] married women.} [Quran 4:24]
The second: She married a non-Muslim man; it is not permissible for a Muslim woman to marry a non-Muslim man, according to the consensus of all Muslims. Allah Says (what means): {And do not marry polytheistic men [to your women] until they believe.} [Quran 2:221]
Each of these two considerations is sufficient to indicate the invalidity of this marriage and the obligation on her to separate from that man.
There is nothing wrong with her husband keeping her in marriage bond if she had repented from her sin and turned to Allah, otherwise there is no good in him in keeping such a woman as his wife.
It should be noted that your friend must have made sure that she was not pregnant by her observing three menstrual cycles – and according to the view of some scholars one menstrual cycle is sufficient – before he has any sexual intercourse with her.
However, divorce does not take place by either of these two expressions; i.e., his saying: ''You got married to so and so" or "You are married to him".
For more benefit on the absolute prohibition for a Muslim woman to marry a non-Muslim man, please refer to Fatawa 90619, 87151, 274252, 124877, 84265 and 88406.
Allah Knows best.