The pun is that he was holding a muffin up to her face, and he called her a muffin, which has always been one of those cute names that people in a relationship will call each other. Fairly simple.
>Guy is a god damn savage
>This guy a god damn savage
>This is guy god damn savage
>This is a guy damn savage
>This is a god guy savage
>This is a god damn guy
Ok, only the first and the last make any sense grammatically, and I have no idea how you made either of those mistakes.