The NIV words it as such:
Proverbs 31:3
Do not spend your strength on women, your vigor on those who ruin kings.
Of verse three and the passage beginning in verse ten, each is referring to an entirely different class of female. One, chooses to be a woman -- a wife of noble character -- the other, chooses to be something far less than that. The female referred to in verse three will tear you down, deter you from your purpose and achievements, and even destroy you. The other, the wife of noble character, will build you up, enrich your life, and help you to accomplish your purpose.
A prominent part of a Godly marriage consists of each spouse helping to better and grow the other. The husband grows and plants his wife's heart with love and strength helping her to blossom into the fullness of her beauty and womanhood. The wife nurtures, encourages, and builds her husband's heart, helping him to reach his potential as a man.
The passage beginning in verse ten tells of a single, very special, extremely priceless woman -- a woman who betters her husband and his life in every way. Verse three refers to the many females -- likely harems in the case of King Lemuel and in our case, the many promiscuous materialistic females a guy will encounter living in modern times -- who will bleed a man dry of his drive, his life force, and his finances. The woman described in the other passage increases and enriches all these things in a man's life.
In essence, King Lemuel's mother is instructing him to not squander his strength -- a.k.a. his capacity to be a great king or, as it applies to we normal guys, our capacity to make a living, build a life, and accomplish our purpose -- in an attempt to purchase the love and devotion of the many females whose only interest is in getting all the money and attention they can out of a man, instead using their own life force, their femininity, and their beauty to build him up and add value to his life.
His mother is instructing him to not take the gift of his sexuality (referred to as his vigor) -- a.k.a. his capacity to bond and become one with the right woman -- and use it up or defile it by trying to bond with all the wrong women. Basically, don't sleep with and squander your drive and energy on one woman after the other but rather, save those things for the right woman, the woman who loves you enough to become your wife and spend her time as such blessing you, increasing you, and building you up, rather than tearing you down or using you as a tool to elevate herself or feed her own selfish desires.
