The newly 21-year-old diva has come a looonnnggg since her days on Barney and Friends as proven yet again with her appearance on The Tonight Show yesterday.
The former child star *GASP* even had a shot of Jack Daniels Whiskey to ring in her birthday on Sunday.
Ahhh! She's growing up too fast! We wish she'd slow down! LOLz!
But did the leather-clad lady get wasted for the big day or did she keep it classy??!
Selena admitted she was just a bit hungover, but that didn't stop her from delivering an epic live performance!
Ch-ch-check out the video and watch her Slow Down … AFTER THE JUMP!!