Answer:
I am your mother's brother's only brother in law. Who am I?
What does someone else have to take before you can get?
What has no hands but might knock on your door, and if it does you better open up?
A man goes out in heavy rain with nothing to protect him from it. His hair doesn't get wet. How does he do that?
A cloud was my mother, the wind is my father, my son is the cool stream, and my daughter is the fruit of the land. A rainbow is my bed, the earth my final resting place, and I'm the torment of man.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?