In their Merriment, they Backbite

Question :

My relatives enjoy merriment, but while in a state of levity, they backbite, play cards, spread rumors, and commit other sinful acts. Can I sit with them? Most of them are not only close relations to me, but are also close friends.

Answer:

In their gatherings of levity and mindlessness, the people you described are in fact in their foolishness - eating the flesh of their brothers. Allâh said in the Qur'an:
"Neither backbite one another. Would one of you like to eat the flesh of his dead brother? You would hate it."

These people, who are eating the flesh of their brothers - and we seek refuge with Allah from that are committing one of the major sins. It is obligatory for you to give them advice; if you accept your admonishment and stop behaving that way, that is fine. Otherwise it is obligatory for you to excuse yourself from the.
"Already has He sent down to you in the Book, that when you hear the Ayat of Allah being rejected and mocked at, you are not to sit with them until they turn to talk other than that, if you did, you would be like them. Indeed Allah will gather the hypocrites and the dishelievers in Jahannam, altogether."

Since Allâh has made them equal in judgement, those who sit with others who disbelieve in and mock Allah's verses, and since that behavior is such a grave matter that removes one from the religion, then whoever participates in disobedience that is less than that, like these people who accompany those disobedient ones who disbelieve in Allah's verses and mock them then whoever sits in a gathering where backbiting is present is like the backbiter in sin. So you must leave their gathering and not sit with such people.

Your excuse that you are related closely to them will not benefit you in the least on the Day of Judgement or on the day when you will be alone in your grave. At any rate, you will either be forced to leave them in a short time, or they will be foced to leave you. when each one will only have his own deeds. Allâh Almighty said in the Noble Qur'an.
"Friends, on that Day, will be foes to one another, except those who have Taqwa."

Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 7 Pages 356-357