Does entering YouTube and being accidentally exposed to pornographic images, after having sworn by triple divorce not to enter pornographic websites, count as breaking the oath?

Praise be to Allah who has bestowed upon you repentance. The "YouTube" website is not exclusively pornographic; it contains both good and bad. If you access it with a good intention to watch something beneficial for your religion or your worldly life, then the oath of divorce does not take effect. If your eyes inadvertently fall upon pornographic images and you immediately avert your gaze, there is no sin upon you, for Allah the Almighty says: "And there is no blame upon you for that in which you have erred, but [there is blame for] what your hearts intended. And ever is Allah Forgiving and Merciful."