Selena Gomez spent an entire week celebrating her 21st birthday. While we get that it's a milestone birthday and most people her age want the fun to last, the singer kept the party going and going and going.

Her ex, Justin Bieber, who she admitted she enjoys spending time with even though they are O-V-E-R, was on hand to help her celebrate in Malibu on Saturday, July 27.

Actresses Julianne Hough and Nina Dobrev were also there at the gypsy-themed event at the Revolve Beach House. Also on hand at the birthday bash: Belly dancers, mermaids (who were swimming in a nearby pool), tarot card readers, and a contortionist. Oh, and the 3-tiered chocolate cake that supposedly had Bieber's face on it was designed by Cake Divas. It was beautified with jewels and exotic animals (the latter were painted on). Although we love them, this was no Carvel cake.

E! reports that Sel's ex-'Boyfriend' showed up with a crew, rolling deep with bros and bodyguards, arriving in that cheetah print Audi R8. Yes, cheetah print.

The festivities carried on until 2AM and that's when Sel exited in the same car as the Biebs. Let's hope Bieber didn't drive like a maniac, endangering locals by driving like an idiot.

Remember, she said they enjoy each other's company still and that can mean a WHOLE lotta things.

A source said they crashed out at his Calabasas crib.

Earlier in the week, Sel and her gal pals got together in West Hollywood to celebrate her birthday. See those fun times here.