Assalaamu alaykum. What is the ruling on a 14-year-old boy who used to rub up against his smaller cousin. He ejaculated sometimes, so he was mature. He ended up penetrating her, which is considered rape. He says that he knew that he was doing wrong. The victim remembered this and accused him now, almost 15 years later, as the victim was very small when it happened and either forgot or blocked it out or did not comprehend it at that time. She also wants him to go to jail. He has a wife and a kid now.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.

There is no doubt that this boy has sinned and wronged this girl, and he did what he did while he was accountable for his actions since he had already reached puberty (he ejaculated, as stated in the question). ‘Ali, may Allah be pleased with him, narrated that the Prophet, sallallahu ‘alayhi wa sallam, said, "There are three (persons) whose actions are not recorded: a young boy till he reaches puberty, a sleeping person till he awakes, and an insane person till he regains his sanity." [Abu Daawood]

It is incumbent on him to repent to Allah, The Exalted, and ask this girl to pardon him. She should forgive him, bearing in mind the great rewards for pardoning, which are not comparable to retaliation, the injustice of others. The Islamic Sharia praises those who pardon people and clarifies that it is one of the reasons for earning forgiveness from Allah and attaining a raised status in the worldly life and the Hereafter. Allah, The Exalted, says (what means): {...and let them pardon and overlook. Would you not like that Allah should forgive you? And Allah is Forgiving and Merciful.} [Quran 24:22]

Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet, sallallahu ‘alayhi wa sallam, said, "Allah does not increase the one who pardons except in honor." [Muslim] Moreover, this incident took place a very long time ago, and Allah screened both of them from the people, so she should not uncover what Allah has screened. For more benefit, please refer to fatwa 84351.

If she chooses to claim her right from him, she is not entitled to raise the case to the judge to put him in jail; rather, she is entitled to take a bridal gift from him equivalent to the bridal gift that a woman of her social standing normally takes (as a bridal gift). This is the view of the Shaafi‘i and Hanbali scholars. The Shaafi‘is held that she is entitled to a bridal gift equal to the bridal gift of a previously married woman plus a compensation for making her lose her virginity (arsh al-bakaarah). The Hanbalis, on the other hand, held that she is entitled to the bridal gift of a virgin without compensation for losing her virginity.

Allah knows best.