Bieber. (Jason Merritt/Getty Images)Armstrong. (Chelsea Lauren/WireImage)There's something about Justin Bieber that just drives Billie Joe Armstrong crazy. On Sunday, the Green Day frontman checked into rehab for an undisclosed "substance abuse" issue two days after having a massive meltdown onstage at the iHeartRadio festival, during which he shouted, "I'm not f--king Justin Bieber!" after the band's set was cut short … even though the "Boyfriend" singer was not even there. Armstrong's rant was ignited by a "1 minute" warning that flashed on a teleprompter in the middle of their set, instructing the "American Idiot" rockers to wrap it up.

Sara, Jay, and their seven kids (plus a friend) in 2010. (Tom Burns/Getty Images)Seven may be a lucky number, but when that's how many kids you have, it may represent something much different. Mom-of-three Sara Evans more than doubled her brood in June 2008 when she married sports radio host Jay Barker, who had four children of his own. But while seven kids (ranging in age from 7 to 13) could make any person pull their hair out, the country singer insists "I'm not overwhelmed." So what's her secret?

Pink on Today. (WireImage)Rain or shine, Pink was going to perform on "Today"— and unfortunately for her and her fans, it was raining. The "Blow Me (One Last Kiss)" singer rocked out in front of soggy New Yorkers on Tuesday morning, the same day her sixth album, The Truth About Love, was released (and went straight to No. 1 on iTunes). "Thank u to everyone who came to play in the rain with me at the today show!" she tweeted after the concert. "You guys are hardcore!!!!! I love you for it So! Much! Fun!"

Gaga arriving at the party; head tattoo. (WireImage/littlemonsters.com)Well, now we've seen everything. On Thursday night, Lady Gaga celebrated the release of her Fame fragrance by getting a tattoo on her newly-shaved head — while lying inside a giant perfume bottle, which was placed in the middle of the party. As fans and friends looked on, the "Born This Way" singer was curled up as a gray-haired man in a white shirt and suspenders inked a Statue of Liberty-esque cherub with wings on the back of her head, which she shaved days earlier as an ode photographer Terry Richardson's mother who recently passed. But not before she downed tequila shots and smoked a bunch of cigarettes to numb the pain and calm her nerves.

Stefani covers Marie Claire.Gwen Stefani is getting better with age — of course, we can tell that by just looking at her. But creatively, she's also maturing. In fact, the No Doubt singer tells Marie Claire that her band's upcoming sixth album in 20 years, Push and Shove, is "my favorite record. I mean, your favorite record is always the last one you did, but it really is — it's a really great record."

Rihanna and Chris Brown and the 2012 VMAs (Twitter)Two weeks after Rihanna confirmed she had made peace with Chris Brown, who famously assaulted her in 2009, all eyes were on them at the MTV VMAs. Would they give one another a simple nod from across the room? Perhaps a friendly wave? What actually happened was a bit more than that — and it's generating a lot of buzz the morning after the award show.

During the Thursday night show, the 24-year-old Barbadian beauty collected her Video of the Year award, then exited the stage and was returning to her seat when Brown, 23, stopped her to congratulate her. There in front of the Staples Center audience — and MTV's cameras — they not only greeted each other but also shared a kiss.

ElleBritney Spears knows we're sizing up her clothes, her hair, and her makeup in every photo that's shot of her, whether she's performing at one of her concerts, catching a movie with her boyfriend Jason Trawick and her young sons Sean Preston and Jayden James, or working as a judge on TV's "The X Factor." But the truth is that dolling up for every click of the camera can be exhausting when you're followed by the paparazzi 24/7. Plus, it's just not really her style.

"I love my jeans and my sweats — I'm really just a tomboy at heart," the Louisiana native reveals in a new interview with Elle. "So it's really hard for me to be like Kim Kardashian and be makeup- and hair-ready every time I go out of my house. I'm not a believer in that, you know? On the other hand, when you do wear those sweats, you're like, 'Oh God, I should step it up a notch.'"

Christina Aguilera (Robert Erdmann/Lucky)

Christina Aguilera is proud to be bootylicious. While shooting the music video for her song "Your Body" recently, she had on an outrageous getup, which included a pink wig, sky-high stripper stilettos, and enough rings to accessorize you and all your friends. But it was the dress that was most eye-catching. We noted that the mesh-laden mini was "literally bursting at the seams" when we first saw the photos.