Is a wife sinful for denying herself to her husband to force him to stop talking to girls over the phone or chat?

It is not permissible for a man to engage in illicit relationships via phone or internet, and his doing so is a sin and an act of disobedience, becoming more reprehensible if he is married. The wife should advise her husband and remind him of Allah. If he responds and repents, then all praise is due to Allah. But if he persists, she has the right to seek divorce. If she chooses to remain with him, she is not permitted to refuse him access to her bed if he calls her, and she must fulfill his right as long as the marital relationship exists, while informing him of her displeasure with his actions and advising him. She may also threaten him with seeking divorce if he does not repent.