"I'm well aware. Why d'you think 'm going t'all the trouble, eh?"
The immense fear Jack feels when thinking of dying again is all but crippling. It's all he can do not to shake visibly and his heart skips a beat each time. He's flirted so close to death all his life, but now that he's had a taste of what waits for him, he has to be sure it can never come to that. He has to know he can not die so he's free of the fear and free to live again.
As the words sink in, though, the pirate tilts his head curiously and looks into the seal's dark eyes. "...They asked for my life an' you chose t'spare me? You've my thanks, then."
And that's that. Jack gets up and heads out of the brothel, waiting for the selkie to follow.