Oh, let's be honest it was a celebrity blowout with guests like Sam Smith, the ladies of HAIM, model Karlie Kloss, Beyonce, Jay Z and Justin Timberlake, who apparently didn't mind wearing an adorable pile of poo emoji mask.

In a photo nonetheless! What a good party guest, seriously. She also posted a photo of a special gift her best Girls friend, Lena Dunham gave her: a necklace with a picture of her little kitty, Meredith Grey. It's now her "new most cherished possession."

To cap it all off, Swift then had herself a little dance party at the Barclays Center in Brooklyn on Sunday (Dec. 14) where JT was playing all the hits on his 20/20 Experience World Tour.

Queen Bey even joined in when her hubby hit the stage to perform "Holy Grail" alongside Timberlake.