Now how I remember you
How I would push my fingers through
Your mouth to make those muscles move
You use your mouth to speak. Anne Frank’s “mouth”, therefore, is her diary. He (Jeff) pushes his fingers through her mouth; he pushes his fingers through the pages of the book. He makes her speaking muscles move by moving his fingers through the book’s pages.
It also deserves a mention that this is a thinly veiled sexual metaphor.
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