What would social media be without a little heated conversation? This week the chatter fell upon Julianne Hough's hair, which grew a few inches (cough, extensions). There was also a brief Twitter war between Selena Gomez, Ariana Grande, and Miley Cyrus followers over the stars' competing Jingle Ball beauty looks. Kate Middleton in a ponytail (gasp!), Lea Michele's sultry album cover hair, and Olivia Wilde's MILF beauty routine were also hot topics this week. See all your favorite beauty news from the week that was, and make sure to follow POPSUGAR Beauty on social media, including Pinterest, Facebook, Twitter, Instagram, and Google+.