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 is His slave and Messenger.
First of all, we thank and praise Allaah Who guided you to Islam and we ask Him to make you firm and steadfast on His Religion until the Day you meet Him.
We advise you to seek beneficial knowledge, perform good deeds and befriend righteous and pious women, as these are the best things that help a Muslim woman remain steadfast on her religion.
May Allaah reward you for being keen on pleasing Him and for asking about the religious matters that concerns you.
As regards the Misyaar marriage, then it is a marriage that fulfils the conditions of a correct marriage, like the consent of the guardian and the presence of two witnesses while the wife renounces some of her rights, like her husband staying overnight with her and spending on her, and the like. Nonetheless, the fact that the wife renounces some of her rights does not affect the validity of the marriage; for more benefit on the ruling of Misyaar marriage, please refer to Fatwa 82104.
On the other hand, your husband should not have lied to you, but since what happened had already taken place that your husband married a second wife, then he did not do except what Allaah permitted him to do –meaning that Allaah permitted a man to marry more than one wife. For more benefit on the wisdom of polygamy, please refer to Fataawa 90132, 86818 and 84184. Therefore, we advise you not to be preoccupied about this marriage, but you have the right to ask your husband about your rights on him, among which is having sexual intercourse with you; a husband is obliged to keep his wife chaste and having sexual intercourse with her is her right.
If a husband is not able to fulfill this right, then his wife has the right to ask him to divorce her because of the harm on her because of him not having sexual intercourse with her, or she may be patient with him hoping that Allaah will rectify their affairs. It might be that her staying with her husband while he is negligent about this right is better than separating from him especially if she is blessed with children with him because divorce may lead to the disunity of the family.
The following matters should be mentioned:
1- It is not permissible for a wife to ask her husband to divorce his second wife.
2- The parent who has the right in fostering the children, has no right to prevent the other parent from seeing his/her children.
3- Having sexual intercourse is a right of the wife as we have already mentioned, so the husband has no right to prevent his wife from this right without her consent, and no one can give the permission to the husband about this.
4- It is not correct to link the problems that happened between you and your husband to the matter of your religion and your righteousness, rather, you should be concerned about learning the matters of your religion and you should seek to purify yourself in any case. This can be done by striving against one’s own self and by seeking the help of Allaah.
Allaah Knows best.