She feels attracted to someone other than her husband
Question

                I am a married woman with kids.My husband treats me very well and takes care of me well.Recenetly one of his relatives a guy almost about 10 years younger than I am and I became very close and before I knew it he fell in love with me.I told him that its not on but his feelings for me grew and grew. I asked him to make Istikaara namaaz and ask Allahs guidance and he did so and he performed his namaaz thrice and all 3 times he got a positive answer with me.I dont see him but I know that since his a very decent boy and sincere. I have also grown to have feelings for him but I try and hide it all the time.Is it possible for me to make istikaara whilst married and also what do we do? Please make duaa for me and help me in this very diffcult situation as I dont want to cause any pain to my husband and my family.
Praise be to Allah.
    Allaah has caused men to be attracted to women, and women to 
    be attracted to men, and this inclination sometimes results in haraam 
    relationships such as zina, and sometimes it results in permissible 
    relationships such as marriage. Allaah has made the wife a covering for her 
    husband and has made the husband a covering for his wife. Allaah says 
    (interpretation of the meaning): 

    “They are Libaas [i.e. body-cover, or screen, or Sakan 
    (i.e. you enjoy the pleasure of living 
    with them)] for you and you are the same for them”

    [al-Baqarah 2:187]

    One of the blessings that Allaah bestows upon some spouses is 
    that He creates love and compassion between them, and helps each of them to 
    do that which causes harmony to grow in the family and ward off disputes and 
    arguments. This is a very great blessing indeed, which is not appreciated by 
    anyone but those whose family relationships are disrupted and disputes and 
    arguments arise amongst them, which turn the marital relationship into an 
    unbearable hell. If that happens, each spouse starts to dream of a stable 
    family life, and the man wishes for a wife with whom he can live in peace, 
    and the wife wishes for a man with whom she can live in peace. 

    From your question, it may be understood that Allaah has 
    bestowed all these blessings upon you, so what you should do is be grateful 
    to Allaah for this great blessing and strive to preserve it and the family 
    with which Allaah has blessed you, for millions of women wish that they 
    could be in the good situation in which you are, but you do not appreciate 
    its value. 

    You should note that it is not permissible for a woman to 
    form a relationship with a non-mahram man. If she is married, then such a 
    relationship is even more haraam, because it is a transgression against the 
    husband’s rights and honour. 

    Based on this, it is not permissible for you and this evil 
    lover to pray istikhaarah, because istikhaarah is only prescribed in cases 
    where it is not clear if the matter is good or bad, and the Muslim does not 
    know where his interests lie, so he prays istikhaarah asking that Allaah 
    will help him to attain that which is good if it is good, or divert it from 
    him if it is bad. But if a Muslim prays istikhaarah with regard to 
    disobeying Allaah or going against His commands, this is a sin for which he 
    has to repent to Allaah. 

    To explain further: if a Muslim woman prays istikhaarah about 
    marrying someone other than her husband when she is still married to her 
    husband, then in fact she is praying istikhaarah about wrecking her home and 
    family, and praying istikhaarah about hurting her children, and praying 
    istikhaarah about divorcing a husband who is treating her well and taking 
    good care of her. So she is praying istikhaarah about betraying him and 
    stabbing him in the back by tearing apart his family, so that his home and 
    hers will be destroyed at her hands. She is praying istikhaarah about 
    responding to great kindness and good treatment with a great wrong and 
    denying the rights of one who has treated her well. 

    All of these factors and many others apply to the istikhaarah 
    prayer that you offered. 

    As for the positive result that you say your friend got, 
    undoubtedly this is a case of the shaytaan making following one's whims and 
    desires appear attractive. The Muslim should not pray istikhaarah about 
    doing something that is haraam, so how can he pray istikhaarah and claim 
    that he got a positive result?! 

    Moreover, after praying istikhaarah the Muslim should resolve 
    firmly either to do it or not to do it. Whatever Allaah makes easy for him 
    is what is good, but if he waits until he feels good about it or sees a 
    dream and the like, these are usually illusionary matters on which no shar’i 
    ruling can be based. 

    Based on the above, you should push away all whispers from 
    the shaytaan that have to do with this matter, and do not give evil any way 
    of reaching you or your family or children. You should realize that you have 
    fallen into a trap of the shaytaan, because he has made you attractive to 
    this young man and has made him attractive to you so that he may achieve 
    what is his greatest dream, namely the destruction of a stable, believing 
    Muslim family and the divorce of two spouses who love one another, and the 
    neglect of their children. 

    Thwart the plans of the shaytaan by not letting this young 
    man destroy your life and your family. Cut off all means that may enable him 
    to continue to have any place in your life. 

    One of the ways in which you can ward off these devilish 
    whispers is to ask yourself the following questions and answer them 
    honestly: 

    1.If this young man is righteous, 
    then how can he accept to destroy the home of his Muslim brother and split 
    up his family? 

    2.If this person really loves 
    you, why is he striving to wreck your home and destroy your family? Does he 
    love you or does he love himself and is only looking out for his own 
    interests and desires?

    3.If this young man were to get 
    what he wants and you were to get divorced from your husband – Allaah forbid 
    – what would be the fate of your children who are a trust about which Allaah 
    will question you on the Day of Resurrection?

    4.What guarantee do you have that 
    this young man will treat you as nicely after marriage as he does now? It 
    should be noted that many marriages that are based on “love” are doomed to 
    failure after only a few months, because they are based on a weak 
    foundation, not on a foundation of pleasing Allaah and His Messenger  
    (peace and blessings of Allaah be upon him).

    5.Do you expect that trust will 
    last between you after you get married? If he loves you although you are 
    married, then how can you be sure that he will not fall in love with someone 
    else who is also married or not married? How can he trust you if you 
    destroyed your home for his sake? This pattern may be repeated when you are 
    married to him. These doubts will persist and will be a cause of anxiety for 
    both of you. You have both accepted something haraam and you have not 
    refrained from establishing a haraam relationship even though there is a 
    legitimate marriage contract between you and your husband, so who can 
    guarantee that it will not happen again?

    With regard to your request for a du’aa’, I ask Allaah, the Most High, the Almighty, by His grace and favour, to make goodness easy for you and to ward off all evil from you, and to continue to bless you and your family with stability and love, and to keep you and your husband and children safe, and to ward off from you the whispers of the shaytaan and his making falsehood attractive. 

    And Allaah knows best.