You probably couldn't take a step at Jennifer Lopez [1]'s 47th birthday celebration in Las Vegas without bumping into an uberfamous celebrity. The sexy "Ain't Your Mama" singer [2], who simply doesn't age [3], had all her favorite people in tow for her big day — and they all just happen to be stars.

Kim Kardashian and Calvin Harris [4] were there (what did they talk about?), and of course, BFF Leah Remini and longtime boyfriend Casper Smart [5]. There was also a blast from the past with Fat Joe attending. Even soccer player Cristiano Ronaldo took a break [6] from his post-Euro-2016 vacation to visit the US for Jennifer's gathering.

And because J Lo is J Lo, she partied two days in a row! First wearing a custom Balmain brown dress that showed off her impressive abs [7] a day before her real birthday, and then on Sunday July 10, in a sparkly low-cut blue Zuhair Murad gown at the Nobu Villa at Caesars Palace for a karaoke-filled night. Scroll ahead to see all the Instagram photos from the weekend.