I was listening to a lecture by Swami Prabhupada about relationships that do not endure. He was saying that a father has a small son. He is so affectionate to his son, the son is so affectionate in this relationship. His affection is so deep and Prabhupada said it's not endurable. Later it will change - that same son will revolt against his father. He will disappoint his father. He will hurt his father who will feel like: 'I've done so much for him..how can he treat me like this?'
Prabhupada says it will not endure. Nothing endures except relationships that are spiritual.
(Kadamba Kanana Swami,
South Africa 2009 )