What is the ruling on an emotional relationship online between a young man and a young woman who intend to marry, given that the young woman is already engaged to her cousin?

Online conversations between young men and women are among the greatest causes of contemporary tribulations (fitan). This is a relationship forbidden by Islamic law and is not permissible to establish, due to the corruption, violation of honor, and calamities it leads to. This reprehensible relationship must be severed immediately before incurring the wrath of Allah the Almighty.