It's the official start of summer and we're keeping up with the Kardashians -- even on their family vacation.

The crew visited Bora Bora last week, and they had some add-ons: Kim's fiancé of a few weeks Kris Humphries and Kourtney's boyfriend -- and father of her 18-month-old son -- Scott Disick. Younger sister Khloe -- who is lending her face and curves to Nivea's Goodbye Cellulite, Hello Bikini! Challenge -- stayed at home.

Kourtney and Kim -- though clearly sisters with their identical tans and long, shiny tresses -- sported distinctly different styles on the trip. The elder Kardashian went for a more subtle, laid-back look and her newly engaged sister was seen rocking bright, stand-out suits.

Check out our gallery above for a look at the sisters' varied styles and pre-teen Kylie's swimsuit of choice. And you'll never guess which one of our StyleList bloggers gave Kim a run for her money in a leopard print bikini!

And remember this beach-side editorial that Kim shot with Justin Bieber?