A husband complains about his pregnant wife's continuous communication with her sister's husband via social media, despite them living in the same residential complex. He forbade her from communicating, changed her phone SIM card, and she swore not to communicate, but she broke her oath and continued talking to him and exchanging video clips. He threatened her with divorce if she does not stop this communication, and he asks for a solution.

All praise is due to Allah, and prayers and peace be upon the Messenger of Allah, and upon his family and companions. As for what follows:

It is obligatory for the wife to obey her husband when he forbids communication with her sister's husband without a need. This falls under the guardianship (Qawamah) that Allah has granted to the husband. If she does not obey, he may discipline her through admonition, then by abandonment (Hajr), and then by non-violent striking.

Regarding the oath: if he intended it as a threat of divorce, then the divorce does not occur. But if it was a suspension of divorce upon her communication with her sister's husband, then divorce occurs if she communicates with him.

And Allah knows best.