The Torah's requirement is not to be lust free, but not to go after the lust that you discover yourself having.
I'm not sure what you mean to say, but I think it is assur to lust after your friend's wife even if you do not act upon it. In fact, it may even be one of the aseres hadibros.
Excuse me if I wasn't clear. As far as I understand, the issur is not having the lust. It is holding onto it and/or not doing whatever is needed to get free from it once we see that we've got it. No?
Otherwise, do you mean to say that I am doing wrong by wanting to do an aveiro? "Lo sasuru acharei l'vav'chem" means that l'vav'chem is telling you to do crazy and stupid stuff - and Hashem tells you: "don't follow it and get lost in the distraction to life it is suggesting for you! I love you too much and life is too precious for that junk!"
Hashem is definitely for the addict, too! Dodi li!
No?
I know we tend to get very spiritual here (especially right after acting out! ) but really - lets not confuse 'states of being' with 'avodah'. A good yid is supposed to naturally be averse to lusting or even wanting anything kneged R'tzono Yisborach. But that is not shayach to us, generally, and if I look at that and (inwardly) demand that of myself, it will destroy the likes of me. Completely. There will not be a shoresh v'anaf left of me after a while. Instead, I need to admit where I am holding, how vulnerable I am, and give it all to Hashem - meaning I depend on Him to assist me to do His work today, imperfectly. I cannot afford to intentionally use lust and act out, though - that is not negotiable. But I must give the credit to Him for every step - especially for my sobriety. That is just how it works for me.
And the fruit of that surrender to the truth about me (first to myself, and then to Hashem) is: losing the desire for what is not good for me most of the time. And getting the help to avoid it when I am feeling crappy. Hashem helps if we admit the truth and ask for His help and try to do for Him and others. I have met many who are experiencing that. It seems that the next gift is something like actually desiring what He wants more and more... and on and on - you do the math. There are changes that are in my very bodily reactions to stuff that I cannot explain using my bechirah alone - it must be a gift.
Love you, chaver!