You're taking this verse out of context.
It's saying that if you feel temptation inside, you haven't done anything wrong, but the possibility of fulfilling your inner thoughts exists as temptation grows so better to nip it in the bud. Years ago there was little concern of acting upon your inner thoughts, but as the world advances and opportunities become easier to act upon to fulfill temptation, it's better to erase your inner thoughts of desire to prevent acting upon them further.
If you continue to read your quoted verse, under the title 'Adultery of the Heart', it will clarify for you.
In reality, there is no direct mention of pornography in the Bible. It's left to interpretation from association, as you've done above.
For the record, I've counted I believe 4 things thus far you've done that go against the Bible's word yourself while contributing just on 1 page here. Pointing a finger at someone else yields 3 pointing back your way my friend.
Please stay and join us, it's a lot of fun in this thread. If you feel otherwise to someones statements, do not hesitate to reply. If you do so, even if you wish to quote the Bible, just do so with courtesy and not accusatory. Your thoughts and replies will be well received by most if not all in here (the regulars for sure), but nobody here wants to be spoken down to. We're all the same.
Welcome to our group.