Possibility of being a sperm donor, is it a good idea?

My friend asked me if I wanted to be a sperm donor for he and his wife, I am male, btw. I am willing, and we have already talked to my wife and she is fine with it. My friend has low count, motility, and morphology. <br><br>Here are my concerns. <br><br>1. I am 46, is this to old to donate at? <br><br>2. This will be for a home insemination, is this a good idea, or should we go through an REI Clinic. <br><br>3. Could this hurt my marriage? <br><br>4. How do we talk to our kids about this, we have a 3 and one on the way. <br><br>5. How do I explain this to my in-laws?