His family impugn the honour of the Prophet (peace and blessings of Allaah be upon him) and insult his companions
Question

                Allaah, His Messenger and the Muslim ummah enjoin upholding ties of kinship, but by Allaah we do not feel this nowadays, because of the bad attitude of the people with whom we live, and because of their bad understanding and their negligence towards Allaah, may He be glorified and exalted. 

My family offend me and they swear and insult my mother if I am present. 

If I am sitting in their house, my family impugn the honour of the Messenger (peace and blessings of Allaah be upon him) and insult his companions. 

Is there any sin on me if I cut off ties with them? 

I ask Allaah to keep us safe and to help you in what you do.
Praise be to Allah.
    Firstly: 

    One should not sit with people such as these who are in the 
    habit of insulting mothers, unless he has no other choice. He has to express 
    his hatred of their actions and attitude, and to do his best to call them to 
    Islam and advise them, so that they will give up these evil actions. 

    If these people are relatives, it is better to strive to 
    uphold ties with them and call them to Allaah, may He be exalted, and to do 
    his utmost in that. If Allaah guides one man at your hands, that is better 
    than red camels (the best kind), and he should not forsake them for his own 
    sake. 

    Secondly: 

    Anything may be tolerated, except insults to our beloved 
    Messenger  (peace and blessings of Allaah be upon him) and slander 
    against his companions and the bearers of his religion. This implies insults 
    against the Lord of the Worlds, may He be glorified, the One Who praised His 
    Prophet  (peace and blessings of Allaah be upon him) and chose him, and 
    Who praised his companions and chose them and honoured them with the company 
    of His Prophet  (peace and blessings of Allaah be upon him). 

    Impugning the honour of the Prophet  (peace and blessings 
    of Allaah be upon him) by slandering his wives or one of them, is an insult 
    against him  (peace and blessings of Allaah be upon him), because he 
    chose her, kept her and was her companion until he departed this world. And 
    it is an insult against Allaah Who chose her for His Prophet and approved of 
    her as his wife and did not tell him to leave her. 

    Such insults can only come from one whose eyes Allaah has 
    blinded to guidance and the true religion, such as the Raafidis and their 
    ilk among the people of misguidance, or those who are influenced by them and 
    have followed their misguidance. We ask Allaah to keep us safe and sound. 

    Hence you have to denounce this grave evil, and explain to 
    your family that this is apostasy from Islam, and it is following the path 
    of misguided sinners. You should warn them of bad consequences in this 
    world, let alone the Hereafter. 

    If they respond, then praise be to Allaah. If they persist 
    then do all you can to convince them, such as inviting one of the scholars 
    to advise them, even if that is done indirectly, or bringing some books and 
    tapes about this topic. If that does not work with them, then you can cut 
    off ties with them or keep away from them. Do that out of a sense of 
    protective jealousy towards your Beloved  (peace and blessings of Allaah 
    be upon him). At the very least you can voice your objections every time 
    they do that, and leave the gathering in that case. 

    Al-Baghawi (may Allaah have mercy on him) said, commenting on 
    the hadeeth about Ka’b ibn Maalik and his companions: 

    This indicates that the people of bid’ah may be shunned 
    indefinitely. … The Sahaabah, Taabi’een and their followers acted in 
    accordance with that, and the Sunni scholars are unanimously agreed that 
    people of bid’ah are to be shunned. End quote from Sharh al-Sunnah 
    (1/227). 

    Ibn Muflih (may Allaah have mercy on him) said: Ahmad said: 
    It is obligatory to shun the one who becomes a kaafir or who commits evil by 
    following bid’ah, or who promotes misguided innovation; this is required of 
    those who are not able to refute it or to speak up against it, or is afraid 
    of being influenced by this. And it was said that he must be shunned 
    altogether, as is the apparent meaning of the words of Imam Ahmad quoted 
    above. Ibn ‘Aqeel stated definitely that this is how it should be, in order 
    to discipline him and bring him to his senses. 

    He (i.e., Ibn al-‘Aqeel) also said: If you want to know the 
    state of Islam among the people of this time, do not look at them crowding 
    the doors of the mosques, or how they raise their voices in the Talbiyah. 
    Rather look at how they interact with the enemies of Islam. Ibn al-Rawandi 
    and al-Ma’arri (may the curses of Allaah be upon them) spent their lives 
    writing poetry and prose, and the former said that religion was a myth and 
    al-Ma’arri said that it was false, disbelieving the book of Allaah, may He 
    be glorified and exalted. And they lived for years and their graves were 
    venerated and their books were sold. This indicates that religious 
    commitment has faded from people’s hearts. Something similar was said by 
    Shaykh Taqiy al-Deen ibn Taymiyah (may Allaah have mercy on him). 

    Al-Khallaal said: Ismaa’eel ibn Ishaaq al-Thaqafi 
    al-Nisapoori told us that Abu ‘Abd-Allaah was asked about a man who had a 
    Raafidi neighbour who would greet him with salaam. He said: No, and if he 
    greets him he should not return the greeting.  

    Al-Qaadi Abu’l-Husayn said in al-Tammaam: There is no 
    difference in the reports concerning the fact that it is obligatory to shun 
    the people of bid’ah and the evildoers among the Muslims, as you can see. 
    The apparent meaning is that there is no difference between the one who 
    openly commits sins and the people of innovation and evildoers. 

    He said: No differentiation is made in that regard between a 
    blood relative and a stranger, if it has to do with the rights of Allaah. 
    But if it has to do with the rights of other people, such as slandering, 
    reviling, backbiting, seizing property by force etc, then it depends. If the 
    person to be shunned and the one who did that deed is one of his relatives, 
    it is not permissible to shun him. If he is not a relative, then is it 
    permissible to shun him or not? There are two reports… 

    Al-Qaadi said: Ahmad only regarded it as makrooh to shun a 
    relative with regard to one’s own rights because of the reports about 
    upholding the ties of kinship. He regarded it as permissible only with 
    regard to the rights of Allaah, and he disallowed it with regard to the 
    rights of anyone else, according to the report of al-Marwadhi about the 
    rights of a stranger. That is because there is no room for compromise with 
    regard to the rights of Allaah but there is room for compromise when it 
    comes to the rights of human beings. This is explained by the words of the 
    Prophet  (peace and blessings of Allaah be upon him): “The debt owed to 
    Allaah is more deserving of being paid off.” 

    The views of most of our companions imply that there is no 
    difference. This is the apparent meaning of the words of Imam Ahmad in some 
    places, and it is more appropriate. The reports about upholding the ties of 
    kinship are should be understood in the light of the evidence about 
    shunning. The rights of human beings may be connected to the rights of 
    Allaah, and they are based on ease and forgiving, unlike the rights of human 
    beings.  

    End quote from al-Adaab al-Shar’iyyah (1/237-238) 

    We ask Allaah to help you and make you steadfast. 

    And Allaah knows best.