Jack winces when his hair is pulled, but allows it since it isn't malicious. He lets her poke and prod at him, only pulling back when she goes for his eyes. That's a bit too far.
He's amused at her familiarity with the telescope and how fascinated she seems to be with every aspect of his attire. It makes her a little less frightening. But not by much. Jack pales when the mermaid takes hold of the compass. His hands fidget and flail, looking for the best way to snatch the thing back from her. "Not good..."
"Careful there, love... No don't... Gah! Just...Give that back t'me, hmm?" Jack pulls it back from her, snapping it shut and clutching it protectively. His compass is not up for barter either.