What is the ruling of Islamic law on repeatedly touching the maternal aunt while fully clothed at the age of fifteen, and is expiation through prayer sufficient?

One must steer clear of sources of temptation and avoid leniency regarding prophetic commands, such as separating children in their beds after the age of ten. Whoever has fallen into these sins must offer sincere repentance to Allah, accompanied by regret and a firm resolve not to return to them. They must also associate with righteous people, adhere to acts of worship, seek forgiveness, and conceal their sin without informing anyone, for repentance alone is sufficient to erase sins. It is important to know that a boy becomes accountable for his actions upon the appearance of any signs of puberty.