Praise be to Allaah.
It is not permissible for a Muslim woman to marry a kaafir,
and the marriage is not valid.
Allaah says (interpretation of the meaning):
“And give not (your daughters) in marriage to
Al‑Mushrikoon[polytheists] till they believe (in Allaah Alone)”
“O you who believe! When believing women come to you as
emigrants, examine them; Allaah knows best as to their Faith, then if you
ascertain that they are true believers send them not back to the
disbelievers. They are not lawful (wives) for the disbelievers nor are the
disbelievers lawful (husbands) for them”
The fact that she was forced into that does not justify her
giving in and surrendering to this marriage. The Prophet (peace and
blessings of Allaah be upon him) said: “There is no obedience to any created
being if it involves disobedience to the Creator.”
This marriage is regarded as invalid, and intercourse with him is zina (fornication, adultery). End quote.
Al-Muntaqa min Fataawa al-Shaykh Saalih al-Fawzaan (3/174).