It is logical that the more a part of the body or faculty is excersised, the stronger it becomes. On the basis of this same principle, the carnal lust will not be satisfied by casting a lustful glance.  On the contrary the root of the evil will become stronger.  One should not be deceived by the satisfaction derived from an evil glance. This satisfaction is temporary.  Soon the urge will assert itself with greater forcee.  It is like a drug addict deriving temporary satisfaction from drugs.  The effect soon dissipates and the urge for more is stronger.

-Malfooz Hadhrat Moulana Ashraf Ali Thaanvi Rahmatullah Alayh