What should a husband do when his wife's family visit for long periods, and he is bothered by their presence and behavior? And is it permissible for him to leave the house for them or inform them of his unwillingness for anyone to stay overnight in his home?

You have the right to prevent your wife's family from staying overnight or residing in your home, but deal with the matter wisely, and do not prevent them from visiting. Be patient with them, enjoin them to do good, and forbid them from evil gently. Explain to them the harms of unrestrained speech in falsehood. Initiate beneficial conversations with them, keep them occupied, and encourage them to listen to admonitions. If that does not help, do not sit with them when they engage in falsehood, and you may temporarily leave the house, dealing with the situation tactfully and wisely. The wife must understand the situation and manage her family, and devise ways to reduce their visits.