Selena Gomez and Kate Middleton's new royal baby have the same birthday...but Selena's no longer a baby. She's allowed to drink!

The star celebrated her 21^st birthday yesterday with friends at Bagatelle in West Hollywood. They appeared to have a great time.

Selena was joined by tons of friends and family including her mom, friend and "Spring Breakers costar" Ashley Benson, and actress and friend Francia Raisa.

Sadly, Justin Bieber wasn't in attendance (or happily...depending on how you look at it).

The group ate tuna tartare, gnocci with truffle sauce, and Caesar salad. The main course was Bagatelle's signature whole truffle-roasted chicken. For dessert? Why, birthday cake-and a bonus "Mega Sundae".

No word on how much 21^st b-day booze was involved.

This classy meal wasn't the only birthday meal, though. Gomez ate Jack n the Box tacos before that and tweeted, "Guess what ... I'm 21. UM, #turnupNOW" along with a photo of herself and a group of friends cracking up.

"Safe to say, I'm enjoying this very much ;)" she added. "THANK YOU for all the bday love! I love you guys so much x."

The birthday was an extended birthday week. On Saturday, July 20, Gomez went to Beacher's Madhouse in West Hollywood with friends including Raisa, Benson, Julianne Hough and Lily Collins. They were all in classic garb for the birthday blowout.. "They were all wearing little black dresses," a source said.

Gomez seemed ecstatic over the birthday then, too.

"I could not have asked for a better birthday," Gomez tweeted on July 22. "This one will be remembered forever."

Bestie Taylor Swift couldn't make it-but she Tweeted a celebratory greeting.

Taylor Swift wasn't able to make either soiree, but she was certainly there in spirit. "Happy 21st birthday to my friend, and the closest thing I've ever had to a sister, Selena Gomez," she said.