Continuing in a short series of simple observations regarding sin found in Proverbs
And now, O sons, listen to me,and do not depart from the words of my mouth. Keep your way far from her,and do not go near the door of her house...
"Do not go near the door of her house": in other words, avoid putting oneself in positions where one will be tempted to sin. The statement is not simply, "don’t go in her door," but rather, "don’t even go near her door."
This is likely a testimony to the very strong attraction that such temptations have over one, much like (to wax astronomical) the gravitational pull of a planet on passing asteroids. If the asteroid stays far enough away, it is unaffected by the strong gravitational pull, but if it comes closer, its course is inevitably altered—and if it comes close enough, it is pulled into the planet, becoming annihilated as it burns up in the planet’s atmosphere.
Sexual sin is like this in that one should not flirt with the temptation; to do so is already to have been defeated.