This had to have been the hottest invite in town!

Gigi Hadid threw herself a 21st birthday at the Nice Guy in Hollywood last night, and everyone from the Kardashian girls to Taylor Swift were in attendance! The supermodel was escorted to the soiree by boyfriend Zayn Malik, and it's a good thing her man was on hand, because she had to be carried to her car at the end of the night. Yikes! The Victoria's Secret bombshell must have one too many drinks now that she can legally do so.

We have to hand it to Yolanda Foster's daughter, because she managed to get some people together that normally would never be caught dead in the same room. John Mayer showed up even though he's fully aware T-Swizz is Gigi's bestie, and we all know how much she hates him for hitting and quitting it back in the day.

Kourtney Kardashian couldn't have been thrilled to be rubbing elbows with Hailey Baldwin, either! After all, they are both banging Justin Bieber and competing for his attention, and the mother-of-three is considering going to some extreme measures to make sure The Biebs is into her. [Kourtney Kardashian] wants to hold onto Justin. With all the models half her age that Justin has been with, Kourtney is feeling insecure. She’s been working super hard on her body and she looks amazing, but she feels like she could look much younger," a source dished to Life & Style.

And then there's exes Kylie Jenner and Jaden Smith. Where was Tyga? He probably won't be too stoked when he catches wind that his girlfriend was hanging out with her first love!