Celebs are fickle fashion creatures. Some weeks they look like a million bucks, and other times you're wondering if they got dressed in the dark. As some of our favorite celebrities hit the red carpet, stepped out for lunch, and attended the hottest parties, we were there every step of the way, tracking the best and worst of this week's celeb style!

Rihanna, Harry Styles, and Kourtney Kardashian looked absolutely fab and sexy this week, while others like Kris Jenner and Britney Spears turned out to be total flops.

Click through the gallery above to check out the best and worst of this week's celebrity style and find out who's Fab and who's a Flop!