ما حكم العلاقة الجنسية عن طريق الهاتف؟

Sexual relations over the phone between a man and a woman who are not married to each other are forbidden, even if it's just a friendly relationship and cordial conversations. If it involves sexual talk or practices over the phone, it is even more forbidden, because sexual talk between spouses over the phone is not appropriate, so how can it be permissible between those who are not married to each other?