A woman from Saudi Arabia cannot sue her half-sister from New Jersey for alleging on an Instagram account that she engaged in frowned-upon sexual relations because it would require a court to become involved in interpreting religious affairs, a New Jersey trial judge has ruled.

The plaintiff, Raghd Alashaal Faisal Alhusaini, who lives in Saudi Arabia, alleged that her half-sister, Malak Alshaal Faisal Alhusaini, defamed her by claiming in social media posts that she had sexual relations with multiple men under a marriage arrangement known under Islamic law as a “Misyar,” according to the court’s opinion.