All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Dear sister, first of all, we congratulate you for the great blessing that Allaah has bestowed upon you, which is the blessing of Islam. Grace of Allaah should be thanked in many forms among which it is to be keen on what helps you to be steadfast on Islam through seeking the beneficial knowledge, striving to do righteous deeds and seeking the company of good Muslim women.
The husband is Islamically ordered to treat his wife kindly, as the Prophet, sallallaahu ‘alayhi wa sallam, instructed him to do good to her. We have pointed that out in Fatwa 88304. Amongst the forms of bad treatment is that the husband insults his wife and it is even worse when he does that in front of his son.
On the other hand, smoking is prohibited and if the husband does it in front of his children, the danger will be even worse and thus he will be a bad example for them. Also, amongst the forms of bad manners is the man being untruthful to his wife by telling her, before marriage, that he does not smoke while he knows that she seeks a righteous man. However, it is worth noting that if it does not appear from his current condition that he is still smoking, it is not permissible to investigate whether he stopped smoking or not, because in Islam, the basic principle is that a Muslim is trustworthy unless the contrary is proven.
Similarly, you come to know that if your husband accused that man that he is gay and he has no proof for that, then he has committed a great sin. Allaah The Almighty says (what means): {And those who harm believing men and believing women for [something] other than what they have earned have certainly born upon themselves a slander and manifest sin.} [Quran 33:58]
Hence, he should be advised kindly and leniently regarding that and other religious violations so that Allaah may reform him.
As for his saying that divorce is his choice, then this cannot be correct without exception. Islam has given the wife the right to seek divorce from her husband when there is a valid reason for that. We have stated the sound reasons for seeking divorce from the husband in Fatwa 131953, so kindly refer to it. However, your husband's former untruthfulness is not in itself a valid reason for seeking divorce from him. But if you are harmed by staying with him, then you have the right to seek divorce. Nevertheless, we advise you not to hasten to do that until it becomes clear that it is the right thing for you. That is because the benefit might not be at all times in divorce, especially if the wife has children from her husband. Patience, supplicating Allaah The Almighty and seeking reconciliation may be better than divorce. Kindly, refer to Fataawa 90489 and 118301 on the way of treating the bad character and weak religious commitment of the husband. There is also Fatwa 127405 from which you can benefit if you find out that your husband is still smoking.
After all, if divorce occurred, the mother is entitled to custody of the child as long as she does not get married. If she gets married, then the custody will be transferred to those who follow her according to the order that the jurists have stated and that we have pointed out in Fatwa 84618. If custody becomes the right of the father and the mother sees that he is not qualified for that, then she has the right to refer the matter to the specialized Islamic authorities. The same applies to the case if she has the right to be divorced and the husband refused to divorce her, then she has the right to raise the matter to those authorities.
You should know that your husband's son from another wife is one of your Mahrams. For more information, please refer to Fatwa 88322. The wife is not obliged to accept to live with her stepson except in a special case stated by jurists which is that if the son is still young and she knew about him at the time of consummation of marriage and he has no one to take care of him except his father, then she has no right to refuse to live with him.
As for the income of the husband, the basic principle is that it is lawful. The wife is not required to investigate it, acting upon the basic principle as long as it is not apparent that he earns it from an unlawful source. If so, then it will be prohibited for her to eat from his income if it is wholly unlawful. However, if you do not have money or lawful income to support you, then there is no blame on you to eat from his income, provided that you take from his money only the necessary expenses such as for food, drink and the like. If his money is a mixture of lawful and unlawful income, then eating from it will be only disliked not prohibited.
In any case, if the wife finds out that all the income of her husband is unlawful, it is not obligatory for her to seek divorce; however, she has the right to refer the matter to the Islamic court or whoever acts on its behalf such as the Islamic committees or organizations that belong to the Islamic Centers so that they may remove harm from her through obliging him to feed her from lawful earnings or divorce her. The Shaafi‘i scholars stated that the wife has the right to annul the marriage if the husband spends on her from an unlawful source. In Haashiyat Al-Qalyoobi, the following was stated: “His saying “his ability to earn”, means the lawful earning that suits him. The first criterion "the lawful" excludes the earnings of alcohol, musical instruments and their manufacturing, soothsaying, fortune-telling and the like, in which case she has the right to annul the marriage if he is able to support her with a lawful income.” [End quote]
Allaah Knows best.