Islamic law forbids Muslim women to marry non-Muslim men.
“And do not marry polytheistic women until they believe. And a believing slave woman is better than a polytheist, even though she might please you. And do not marry polytheistic men until they believe. And a believing slave is better than a polytheist, even though he might please you. Those invite to the fire, but Allah invites to paradise and to forgiveness, by His permission. And he makes clear his verses to the people that perhaps they may remember.” (Qur’an 2:221)
As far as the Qur’an is concerned, Christianity is polytheistic:
“And when Allah will say, ‘O Jesus, Son of Mary, did you say to the people, “Take me and my mother as deities besides Allah?”‘ He will say, ‘Exalted are you! It was not for me to say that to which I have no right. If I had said it, you would have known it. You know what is within myself, and I do not know what is within yourself. Indeed, it is you who is knower of the unseen.” (5:116)
“France: Muslim girl’s family shaves her head over Christian boyfriend,” AFP, August 21, 2020 (thanks to The Religion of Peace):
Strasbourg, France: The parents, uncle and aunt of a teenager of Bosnian Muslim origin will face trial in France on charges of violence against a minor for shaving her head because of her relationship with a Christian Serbian boy, prosecutors said Friday.
The girl, aged 17, had her hair shaven off and was also beaten in the eastern city of Besancon on Monday, judicial sources said….
The girl, who arrived from Bosnia-Herzegovina two years ago with her family, had for several months had a relationship with the boy of Serbian origin who lived in the same building in Besancon.
“The two families knew each other and (their relationship) was not a problem, but when they started talking about marriage, the girl’s parents told her: ‘We are Muslims, you cannot marry a Christian’,” Parietti told AFP….
“The first blow came from the mother, then there was an outbreak of violence. She was taken to a room and beaten. She was shaved, according to her testimony, by her uncle – her father’s brother – while being beaten”, the prosecutor said….