Is it permissible for another person to use the marital bedroom for sleeping, such as the husband's mother sleeping in the wife's bed, and does this affect the marital relationship?

The marital bedroom has complete privacy, as it is the woman's dwelling place and sanctuary, where she removes her clothes and is alone with her husband. No one should be privy to its private matters. Necessity may sometimes dictate the entry of a relative into it due to a cramped home or the room being used for sleeping or other purposes, but this is subject to conditions: extreme need for it, not displaying private undergarments, the person entering being trustworthy, and the husband's permission. As for the belief that someone sleeping on the marital bed causes problems, it is an ignorant belief with no basis in Islamic law or in reality. Regarding problems with the husband and his mother, they should be dealt with wisely and skillfully. The husband's satisfaction should be gained through good treatment of his mother, seeking reward from Allah for enduring her harm, and seeking help from Allah.