I have not taken the time to translated it, but I think Reimu is telling yukkureimu to take a bite of herself, since it'll just grow back... Yukkureimu is none to pleased.
Yu: "Where's Reimu's (candy)? Reimu wants to eat sweets too!"
R: "Nooooooope. Eat yourself." Yu: "WHAT DO YOU MEAN!?"
R: "Like this...."
Yu: "Then there's no point!?!??!?" *not sure R: "So noisy---- just munch-munch and it'll pop back out---" *(it's just a play on words/sound... can't really translate that)