Selena Gomez is making the rounds to promote her new album Stars Dance.

Selena Gomez is making the rounds to promote her new album Stars Dance.

Selena Gomez turned 21 on July 22 and partied hard with her close friends, including her first “legal” drink. She told Jay Leno she downed a “shot of Jack,” meaning Jack Daniels Whiskey, which seems to be the drink of choice among rock and rollers.

Welcome to the club Selena, but don’t get too close to Jack.

Janis Joplin made the whiskey famous when she danced around on stage swigging from a bottle in the 1960s. It eventually killed her at 27.

Ever since then, more than one rocker, from Aerosmith’s Steven Tyler to the late-Amy Winehouse has been photographed with a bottle of “Jack.” Winehouse died from acute alcohol poisoning, although she was reportedly drinking Vodka.

“And how many of those did you have?” Jay asked.

“I don’t remember,” Selena said with a knowing laugh. More than likely it was only one shot, although she admitted she was “a little bit” hungover.

“It was fun though, it was good,” Selena. The Stars Dance singer said she went out with friends for dinner at Bagatelle restaurant in West Hollywood on Monday, her official birthday.

Selena Gomez Blows Fuse Over Justin Bieber Question (Watch!)

From there her crew, which included “Spring Breakers” co-star Ashley Benson headed over to Beacher’s Madhouse in LA.

She’s planning to have another, bigger party this weekend that will be Gypsy themed, she said.

“We’re gonna have skirts and tattoos and belly dancers. It’ll be kind of the whole thing, It’ll be fun,” she explained.

And check this out; she’s such a junk-food junkie her friends made her a birthday cake out of fast food Jack In The Box tacos. “My absolute favorite, she said.

Selena is promoting her latest album, but not all of her interviews have gone as smoothly. She hung up on WGN entertainment reporter Dean Richards in Chicago after he asked a question about her ex-boyfriend, Justin Bieber.

Check out her Tonight Show interview below.