What should someone do who has repented from watching pornographic films and masturbation, and has memorized the Quran, if someone asks him about his past sins: should he tell him the truth or lie to him?

Whoever is afflicted with a sin should conceal himself and not inform anyone about it, based on the Prophet's (peace and blessings be upon him) saying: "Whoever commits any of these abominations should conceal himself with Allah's concealment." And his saying: "All of my Ummah are forgiven except those who publicize their sins." The sinner must be sincere in repentance and conceal himself with Allah's concealment, for whoever Allah conceals in this world, He will conceal in the Hereafter. If people ask him about his sin, he should not confess to them, but rather escape the answer through equivocation (tawriya), or say: "I seek refuge in Allah."