Lust is when you constantly desire for sex. Yes it is Human Instinct but as religious people, we are supposed to not think about it until marriage. Reproducing and having kids is what should be on our own mind. Having hope and love, not just to feel to feel that good feeling.
Now we live in world where everything is sexualized, where minors themselves constantly think about it, including you with literal pixels. We have lost our morality.