Practicing this act is a crime and leads to a grave heinous sin which isZina (adultery) and pronouncing marriage words during your conversation does not authorize this act and never considered that you made a marriage contract with that man. Islam blocks the ways that lead to Zina.
The prophet (peace and blessings be upon him) said: “The eyes commit Zina, the hands commit Zina and feet commit Zinna and genitals commit Zinna (Musnad AHmad
This is one of the Satan traps, so repent to Allah sincerely and cut all your relations with such a man since totally.Allah, Most High, says, ‘Do not even come close to Zina. It is a shameful deed and an evil way.’ (Al-Isra’: 32)
Wael`Abdul-Mut`aal Shihab, a Shari’ah researcher stated,
First of all, phone sex and other forms of illicit relations between men and women are strictly prohibited in Islam. Those who involve in such illegal practices should sincerely repent to Allah, stop all illicit relations, fear Allah’s punishment, and be back to the straight path before it’s too late.
As for a man calling a woman “his wife” whether in the phone or during a face-to-face conversation, it does not amount to a legal marriage. A legal marriage has to meet some conditions such as Ishhar (announcement), the payment of the dower, the consent of both parties, the permission of the Wali (guardian) of the lady, and the presence of witnesses.