"Aye. Wish. The one promised t'me, if you recall."
Jack narrows his eyes slightly. Now is the moment of truth for the both of them. Perhaps the selkie will learn a thing or two about the pirate he's trusted with his safety and Jack will learn if selkies can grant wishes or not.
"What it is I want, selkie, is simple. Common, as well, I'd wager. See, I've died once, and I'd like t'avoid repeating the trip. Savvy? So as long a life as you can grant. Forever, if you would be so kind."
He fixes his eyes on the creature, waiting for a response and fully ready to take off after him if the selkie tries to run.