You would tell him why you want one and the benefits of having one.
Explanation:
It would be very hard to persuade anyone to let you get something like a piercing, but if you wanted a good shot at it, I'd first tell him a good reason why you want it. Pathos is common when it comes to begging for something, so tell him how you truly feel about it and how you would feel to get one. Finally, try figuring out the benefits of you having it. Another good thing to try is using an "If-Then" statement. "If I don't get a nose piercing, then ______"
