Selena Gomez's one week birthday celebration is over and done. Of course, the buzz about the big birthday bash continues on countless social networking sites. From Justin Bieber making it to the big day to Gomez partying like "Spring Breakers" with Ashley Benson, here's all there is to know about Selena's 21st birthday week celebration.

Selena Gomez officially turned 21 last July 22, 2013. Yet, the celebrations didn't even end on that day alone. Gomez celebrated it Hollywood style with one week of partying and drinking. A lot of A-list celebrities made it to Gomez's numerous birthday parties of which include Taylor Swift, Lily Collins, Ashley Benson, Julianne Hough, Nina Dobrev, Jaden Smith, Dylan O'Brien and Justin Bieber.

Ironically, Demi Lovato whom Gomez stated should be present at the celebrations was nowhere to be seen in photos on the web. Obviously, the "X-Factor" judge was either too busy to not make it to either one of Selena's birthday parties or scared that the drinking and partying would trigger her once again.

Still, Selena's first BFF, Demi might not have made it, that didn't stop country crooner, Taylor Swift from attending. Despite being super cramped with her tour schedule, Swift made a "swift" appearance at Gomez's birthday party along with "The Mortal Instruments" star, Lily Collins.

The parties didn't stop there because after the first celebration, another took place and this time with a different crowd. Gomez celebrated with "Spring Breakers" co-star, Ashley Benson. As for the last birthday party, Gomez went full on party mode with a gypsy-themed party at Malibu where the one and only Justin Bieber made an attendance bringing along a single red rose.

"Justin arrived at the party in his leopard-print Audi R8," stated a source, adding, "He was casually dressed and carried a single rose."

The PDA was high that night with Justin present at the event. Despite Selena stating she's single, judging from what insiders had to say about what they saw that night, Selena wasn't at all "single and loving it."

"She was all over him. They were definitely touchy-feely and shared some kisses and back rubbing," stated the source.

Check out the slideshow to see more photos of Selena Gomez's week-long birthday celebration.

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