Living wihtout landlords knowledge and seeking forgiveness...only two people were allowed to live in the house in the first place, but later seeked repentance and stopped living there?

There is a brother X who needed housing over summer. He was not sure how long he needed to stay, so he did not want to commit to a contract. There was another group of brothers who told him that he could stay with them, and X agreed and decided to share in the rent. The landlord gives the house out to rent to 2 people. The landlord is non-muslim. X was told that the landlord knows that more than 2 people stay there. So X continued staying. Later X realized that this is not the case and he should not be staying there because only two people are on the housing contract. He repented to Allah and found housing somewhere else. Is this repentance enough or does he need to go to the landlord and seek forgiveness, considering that there may be legal consequences? Also what would be the ruling if brother X knew that only two people were allowed to live in the house in the first place, but later seeked repentance and stopped living there?