Does he have to marry his female relative whom he touched in a haraam manner?
Question

                I am in a horrible situation. I have commited a sin by touching a unmarried women in our relatives. I didn't had exual intercourse but I have touched this lady and she also touched me. Now since this lady is relative ( my mothers brothers daughter) I am scared that this lady will tell others. I have so far led my life as per islamic shariah and people respect me a lot. I am unmarried and I am going to get married to a pios muslimah. Should I am liable to marry this woman whom I have touched? I am very scared of this woman who is neighbour to my family. What should I do to get out of this situation? I know that I have commited a sin. I am preying allah to forgive my sin. I can't imagine marrying this women who always used tricks to attract me. Now I am trapped. Should I tell my parents about it? Do I need to tell the girl whom I am gonna marry about this? Can the girl whom I have touched force me to marry her by islamic law?
Praise be to Allah.
    You have to ask Allaah for forgiveness and repent to Him for 
    what you have done, and you have to resolve never to go back to that. The 
    fact that you touched this woman does not mean that you are obliged to marry 
    her; there is nothing in Islam that compels a sane adult to marry any woman 
    whom he does not want to marry. No marriage is valid unless it meets the 
    necessary conditions, one of which is the consent of the husband who is 
    accountable.

     You do not have to tell your parents or the girl you are 
    going to marry about what happened; rather you are obliged to conceal what 
    you have done, and to repent, and this is between you and your Lord. The 
    Prophet  (peace and blessings of Allaah be upon him) said: “Avoid this 
    filth that Allaah has forbidden. Whoever does any such thing, then let him 
    conceal it with the concealment of Allaah.” (Narrated by al-Bayhaqi; classed 
    as saheeh by al-Albaani in al-Silsilah al-Saheehah, no. 663).

     “Filth” means evil actions and bad speech that Allaah has 
    forbidden. Subul al-Salaam, 3/31

    And Allaah knows best.