Lust and the sexual appetite are two different topics.
Otherwise, God is the cause of sin when He said, “I will greatly multiply thy sorrow and thy conception. In sorrow thou shalt bring forth children; and thy desire shall be to thy husband, and he shall rule over thee.”
That has been my understanding as well. "Lust" is always sinful, and it's not just sexual lust. Lust means being too consumed or attached to material means so much so that you lose self-control. Lust for money, lust for food, lust for sex, etc. whoever said "lust" can be used for good seems to misunderstand whatever he is reading.
So, can you lust after your own wife? Why is that wrong? As I said before Lust, in the dictionary, is defined as: very strong sexual desire
So, what’s being asked is: Is it okay to have a very strong sexual desire for your wife? Short answer is: yes. Not only is it okay, it’s encouraged it seems. Look at Proverbs 5:19. Now, this verse is actually fairly complicated. Translations for it are all over the map. Just for context, Proverbs 5:18 is talking about rejoicing in the wife of your youth.
NIV – A loving doe, a graceful deer– may her breasts satisfy you always, may you ever be intoxicated with her love.
NLT – She is a loving deer, a graceful doe. Let her breasts satisfy you always. May you always be captivated by her love.
ESV – a lovely deer, a graceful doe. Let her breasts fill you at all times with delight; be intoxicated always in her love.
KJV – Let her be as the loving hind and pleasant roe; let her breasts satisfy thee at all times; and be thou ravished always with her love.
Why so many versions? Because the Hebrew is difficult and confusing. But, if you look at the Hebrew, if you take a purely mechanical approach to translation, here is what you get: hind-of love and-ibex-of grace nipples-of-her they-shall-satiate-you in-every-of season in-love-of-her you-shall-err continually
What is clear is this concept of erring. That you will be so distracted by her love (and by the context, it’s obviously sexual) that you will make mistakes. Solomon’s hope for his son was that he would be so enamored of his wife’s body that he wouldn’t be able to think straight in her presence. In short, that he would lust after his bride.
In Song of Solomon (or Song of Songs if you prefer), written by the same man, Solomon, he spends nearly the entirety of Chapter 7 describing the naked beauty of his new wife, and throughout the book you can see their strong sexual desire for each other. You can’t read it and not say that they lust after each other.The problem is that in the Bible, whenever we see the word “lust”, it’s in the context of a sin, or something bad happening, however, it also makes it clear that the lust that is wrong, is lusting after things you have no right to lust after, be it a neighbor’s possessions, or his wife, or even another god. So, just as their is good, healthy, sexual desire in a marriage, and sinful, wrong, sexual desire outside of marriage, there is good, healthy, very strong sexual desire (lust) in marriage, which is inappropriate outside of marriage.
So, can you lust after your wife? Yeah, but that’s good thing. Oh, and wives, you can lust after your husband as well.