Britney Spears sweats juice work out vegas piece of me

Britney Spears went to a rehearsal for her Las Vegas show on Monday, and the pop star carried a bottle of a juice smoothie to sip on.

And not only is she prepping for her residency in Sin City, but she's also going to be working on a new album in the near future. Brit tweeted, "This next record is going to be the most personal record I've EVER made….which means that I need my #BArmy to be a part of it!! ... I wanna see ALL of your photos…old merch, fan art, concert pics...EVERYTHING!! ... I'm gonna pick my favorites to be a part of the next album's packaging :) Can't wait to see what you all send in!! xo."

While all seems well with that, apparently there was a little bit of drama over the weekend when Britney dined out with her boyfriend David Lucado and his friends at the Four Seasons Hotel in Westlake Village. According to TMZ, before Britney arrived, some of the people in the group ordered drinks at the bar, but as soon as the pop legend showed up they ditched their drinks and headed to the table. Britney had made it clear that there was not to be alcohol served when she's present, but apparently a waitress came by with a glass of wine for one of the ladies. Despite the fact that the woman sent the waitress away, Britney was majorly ticked off and left, and as soon as she did one of the gentleman in the group went to the bar and got hammered.

We're guessing Britney wasn't covering his tab...