"But I don’t care either, I don’t care!" said Tonks, seizing the front of Lupin’s robes and shaking them. "I’ve told you a million times…."And the meaning of Tonk’s Patronus and her mouse-colored hair, and the reason she had come running to find Dumbledore when she had heard a rumor someone had been attacked by Greyback, all suddenly became clear to Harry; it had not been Sirius that Tonks had fallen in love with after all. 

"But I don’t care either, I don’t care!" said Tonks, seizing the front of Lupin’s robes and shaking them. "I’ve told you a million times…."
And the meaning of Tonk’s Patronus and her mouse-colored hair, and the reason she had come running to find Dumbledore when she had heard a rumor someone had been attacked by Greyback, all suddenly became clear to Harry; it had not been Sirius that Tonks had fallen in love with after all.