She claimed that she was pregnant with a child from him and had an abortion, and he paid the expenses
Question

                A woman who has a bad reputation and behaves badly claimed that she was pregnant from a friend of mine that she was pregnant. He is married with a young daughter and he swears that he has never had intercourse with her, although something happened between them, but it did not reach the level of intercourse. But she insisted that he was the father of the child in her womb. The solution was that she went to a doctor to abort the child, and because he was afraid of exposure and embarrassment that this woman could cause – because he is married and has a daughter, as I said – he paid for the abortion expenses. It turned out that she was pregnant with a child whose age was six days shy of three months. He deeply regrets what he did, and paying for the expenses of aborting a child whose conception he had nothing to do with. 

My question is: 

What is the Islamic ruling on this action? How can he repent from this deed? Is he regarded as a partner in the killing? How can he repent sincerely to Allaah from what happened? What should he have done, according to sharee’ah, when this girl claimed that he was the father of the child in her womb? I would like an answer soon. May Allaah reward you with good.
Praise be to Allah.
    Firstly: 

    Allaah says (interpretation of the meaning): 

    “And whosoever fears Allaah and keeps his duty to Him, He 
    will make a way for him to get out (from every difficulty)”

    [al-Talaaq 65:2]

    Your friend did not fear Allaah, so He did not grant him a 
    way out. You say that he was intimate with that woman, but he did not have 
    intercourse with her. This is taking lightly and being heedless about doing 
    a haraam action with that woman, which is what led him to commit the second 
    crime (abortion) and made him unable to ward off accusations against him and 
    stand up to this woman properly, because he knew in his heart that he was 
    not chaste and did not resist doing haraam things, even though Allaah has 
    blessed him with a wife and a legitimate marriage. How can a wise man 
    refrain from good, halaal pleasure and replace it with haraam and enjoy it? 

    If your friend had kept himself chaste, Allaah would have 
    granted him a way out, but he transgressed the sacred limits of Allaah and 
    was punished by being caused to fall into another sin. As one of the salaf 
    said:  One of the punishments of sin is further sin, just as the reward for 
    good deeds is more good deeds. 

    Secondly: 

    So long as there is still some goodness in your friend, which 
    is indicated by his regret for what has happened and his desire to repent, 
    then he should note that repentance is not valid and accepted unless it 
    meets three conditions: 

    1 – Regret for what he has done. 

    2 – Giving up the sin. So he must cut off all ties with this 
    evil woman. It is strange that you say that your friend has a daughter. 
    Would he like that for his daughter? No one would want this for their 
    daughters. 

    So he cannot repent if he is still in touch with this woman 
    or any other. 

    3 – He should resolve firmly never to go back to this sin 
    again, and he should resolve to refrain from haraam things and protect 
    himself and his family. He should beware lest he be tested with regard to 
    the closest of people to him as a punishment for what he has done. 

    He should strive hard in acts of worship, and pray regularly 
    on time with the congregation in the mosque if he was careless about that 
    before. He should read Qur’aan a great deal and attend classes, and give a 
    lot of money in charity. 

    Allaah says (interpretation of the meaning): 

    “And verily, I am indeed forgiving to him who repents, 
    believes (in My Oneness, and associates none in worship with Me) and does 
    righteous good deeds, and then remains constant in doing them (till his 
    death)”

    [Ta-Ha 20:82]

    Let him make this sin the beginning of something good for 
    him, by turning to Allaah and keeping away from sin. Many people may be 
    better after sinning and repenting than they were before, if they repent 
    properly and strive to better themselves. 

    And Allaah is the Source of strength.