When tempted, no one should say, “God is tempting me.” For God cannot be tempted by evil, nor does he tempt anyone; 14 but each person is tempted when they are dragged away by their own evil desire and enticed. 15 Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death. (James 1:15)
Some men believe that lust is no big deal. They feed their fantasies with porn and adult movies, and insist that no harm will come because fantasies “aren’t real.” But sin begins in the heart, and it will always effect external actions. It will also be judged by God through eternal death. If you are really serious about fighting sin, you must fight it in your heart, the moment you notice your lust. Waiting until it becomes external is too late.
This is a battle that no one can win by themselves. We all need to repent of our sins and ask God for help.