The point here is that it is wrong to look in order to fulfill some kind of lust, or feed some sort of lust, because if this is the intention, you have already committed adultery in your heart, and eventually you will even commit the sin. But if you are strong, even if you look, and feel any desire, you will have self control, and making the sign of the cross, you will overcome. It is natural to have these desires, but through the power and grace of God, you will keep yourself holy at the same time.