Gregor,
Sorry!
Jesus was referring to "longing" for another woman. Actively desiring and fantasizing about another woman.
Not a random passing thought which most men (you no doubt also assuming you have the dangly things) have on occasion.
Even Jesus himself as a man and human being must have experienced some natural urges for the opposite sex that he must have suppressed.
I've been loyal to my wife for 16 years. Don't try to take away the odd fantasy!