It has recently occurred to me that I have been in intermittent contact with a second cousin who shares my father Y-DNA (subject to any mutations in the last two generations, which should be slight).
I don't believe he has ever had or considered Y-DNA, and I would like to pay for a test for him, as I have no other identified direct male descendants of my father's male line. My father, his siblings, their father and their father are all deceased and I can't identify any other candidate.
What should I say when broaching the subject to him to reassure him about his privacy/keeping control of the results and persuade him to test?
This is similar to Asking distant cousins for DNA? but the difference from that question is that I would particularly like to describe to him clearly and simply what the real risks of DNA testing are, and why some perceived risks are not risks at all. Some of these risks might be privacy risks; others might be risks from what he learns.