Silver Bells and Cockle Shells

*ring ring*

J: Hello?
F: Hey! Oh, you're still at work, right?
J: Yup. 'Fraid so.
F: Sorry to interrupt.
J: Not at all. Always glad to hear from you. Warms the cockles of my heart.
F: Bet you don't know where your cockles are.
J: Uh, sure I do. They're, like, inside. Somewhere. Hang on, I'll check the dictionary.
J: Cockles: 'a common edible European mollusk.' Wrong cockle. Ah yes, here we go. 'Idiom: one's innermost feelings.'
F: But I thought that cockles were an actual part of the heart. You know, ventricles or something.
J: Naw, it says right here that the phrase is idiomatic. Here's another one: 'European bivalve having a rounded shell with radiating ribs'. So, what we have here is a European heart. With valves! Two of them!
F: And 'radiating ribs'?
J: Well, there are ribs 'round the heart. But these are more like 'ribbed for her pleasure'.
F: And if someone else warms the cockles of my wife's heart, then I've been 'cockled-ed'!
J: Okay, the heart is a muscle. And a mollusk - that's kind of a mussel!
F: Uh-huh.
J: Wait, let me check this other link. Um. 'The English phrase cockles of my heart refers to the ventricles of the heart.'
F: Hah!
J: Oh, fine. You win.