Now that's hot!

Paris Hilton and beau River Viiperi jetted from Los Angeles to Mexico today, and not only did they travel with several pals, but the heiress got to meet her man's sister Luna for the first time.

After hopping off the plane, Paris immediately slipped into a bikini and struck a sexy pose. "The weather is beautiful," she tweeted. "Loves it! Can't wait to jump in the pool!"

Can't wait to see more photos from her vacay!