Libido is the sexual urge and it is not a constant factor. It comes in waves. The first wave of libido usually hits someone in their middle teens (age 15-16). This is when some people get married, however judgment is at an all-time low in a wave of libido.
Too often, selection of a lifetime partner is made on the basis of pure animal instinct or exterior appearance. Generally speaking, a person in their teens is not prepared for marriage. A boy in his teens does not have the maturity to take the initiative in making the marriage work. He is 51% responsible for the marriage. A girl in her teens is also not mature enough to marry.
When the first wave of libido occurs, it is one of the most difficult and serious times for young people. God has provided for believers through the control of the Holy Spirit, the means by which one can ride out this wave of libido, for it does subside. 1 Cor. 7:9.
“But if they do not have self-control, let them marry; for it is better to marry than to burn with passion.” (1 Corinthians 7:9, NASB)
The second wave of libido usually comes toward the end of the teens (age 18-19). This is still a very dangerous period for marriage and it is still a period of immaturity. Rom. 13:13-14; 1 Thess. 4:3-5.
“Let us behave properly as in the day, not in carousing and drunkenness, not in sexual promiscuity and sensuality, not in strife and jealousy. But put on the Lord Jesus Christ, and make no provision for the flesh in regard to its lusts.” (Romans 13:13-14, NASB)
“For this is the will of God, your sanctification; that is, that you abstain from sexual immorality; that each of you know how to possess his own vessel in sanctification and honor, not in lustful passion, like the Gentiles who do not know God;” (1 Thessalonians 4:3-5, NASB)
If the man is mature and the woman immature, it can sometimes work. But with two immature people, the marriage is doomed. If the two have had daily exposure to Bible doctrine, have edification complexes well on their way to completion, then there is hope.
Generally, if your spiritual life is right, your judgment will become better after the third wave hits - age 19-20 in a woman and 21-22 in a man. Even then this is very young. Perhaps an ideal time for a person to marry is 25 for the man after the man has had his hitch in military service and a year or two younger for the woman.
Then there is the older man (sugar daddy) who has outlived his first wife and then selects some sweet young thing who is not as interested in his charms as in the thickness of his wallet. This type of marriage usually has little or no divine viewpoint involved.