Will forgiveness for the sin be achieved by enduring the harm and gloating of coworkers who found out about the lapse of watching pornographic websites, or will not confronting them make them persist in their abuse?

It is not permissible in Islamic law to look at forbidden things and pornographic websites. Whoever becomes addicted to them will have a hardened heart and corrupted disposition. Whoever repents with sincere repentance, Allah will accept his repentance. And it is not permissible for anyone after that to reproach him or find fault with him. Abu Dawud narrated that the Prophet, peace and blessings be upon him, said to two men who had backbitten about someone upon whom the hadd punishment was inflicted: "What you have just gained from your brother's honor is worse than eating from him." And he, peace and blessings be upon him, said: "O community of those who have believed with their tongues but into whose hearts faith has not entered, do not backbite Muslims and do not search for their faults, for whoever searches for the faults of Muslims, Allah will search for his faults until He exposes him in his own house." A Muslim should advise colleagues to conceal the faults of whoever has erred and repented, for whoever conceals a Muslim's faults, Allah will conceal his faults in this world and the Hereafter, especially if he is righteous. Patience in the face of people's harm raises ranks and atones for sins.