人之初：At the beginning of life.
性本善：Sex is good.
性相近：All the sex are basically the same.習相遠：But it depends on how the way you do it.
苟不教：If you do not practice all the time.
性乃遷：Sex will leave you.
教之道：The way of learning it.
貴以專：It”s very important to make love with only oneperson.
昔孟母：Once a great mother, Mrs Meng.
擇鄰處：Chose her neighbor to avoid bad influence.
子不學：If you don”t study hard.
斷機杼：Your DICK will become useless.
竇燕山：Dou, the Famous.
有義方：Owned a very effective exciting medicine.
教五子：All his five sons took it.
名俱揚：And their sexual ability were well-known.
養不教：If children don”t know how to do it.
父之過：It is all their father”s fault.
教不嚴：If they had lots of problems with it.
師之惰：Their teacher must be too lazy to tell them.子不學：You may refuse to study this
非所宜：but that is a real mistake
幼不學：If you don”t learn it in childhood,
老何為：you will lose your ability when aged
玉不琢：If you don”t exercise your dick,
不成器：It won”t become hard and strong.
人不學：If you don”t learn sex,
不知義：You can by no means enjoy its sweetness
感謝 rachael 的補充！