I have to find somebody else. Then there is a divorce. Everything is based on the skin, and the skin is temporary. We can never be satisfied, we can never be happy with a relationship based on the skin because our skin is a very temporary thing. A beautiful girl is beautiful for a few years only, it is a fleeting moment only.
Every body gets old, every body gets sick, every body dies.
But we are not the body we are the spirit, the soul. But currently the soul is covered by the material body and we are misidentifying the body with the self. We think if we satisfy the body we will become satisfied. If we are attracted by the skin only, the beauty of the skin, we're bound to be dissatisfied because the person, I, the self, is different from the body. Here Krishna says the soul, even in this life, is changing bodies.