BREAKING NEWS!!! JOHN MAYER CUTS HIS HAIR!!!: After breaking up with KATY PERRY, JOHN MAYER did what a lot of women do when they decide to make a fresh start -- he cut his hair.

Mayer ditched the JOHNNY DEPP-wannabe thing he'd been rockin' for a more clean-cut look, which he debuted over the weekend at a launch party for MINDY KALING'S new television show.

TWITTER WAR - RIHANNA VS. JOAN RIVERS: Like the AVRIL LAVIGNE/CHAD KROEGER out-of-nowhere engagement, I'm betting no one saw this coming: RIHANNA and comedienne, 'Fashion Police' host JOAN RIVERS are entangled in a Twitter War.

Last week, Rivers took to Twitter to tear into Rihanna’s comments to OPRAH about still being in love with CHRIS BROWN. “Rihanna confessed to Oprah Winfrey that she still loves Chris Brown," Rivers Tweeted. "Idiot! Now it’s MY turn to slap her.” RiRi was not amused, firing back, “Joan Rivers wow u really do get slow when you’re old huh? Slap on some diapers.” Rivers then responded with, “Honey, Rihanna, everyone knows: If he hit you once, he’ll hit you again. Read the statistics. PS – Love to have you on Fashion Police!”

Your move, Rihanna.

IS ROB KARDASHIAN HOOKING UP WITH RIHANNA???!!!: Ro-roh! Is ROB KARDASHIAN playing his girlfriend, Rita Ora, with none other than Rihanna? Rob and Rihanna spent pretty much all day Saturday together. First riding go-karts in Burbank, then later at a nightclub in Hollywood. (PHOTO 1) (PHOTO 2) It's cool that you may or may not be getting your swerve on, but why, Rihanna, whyyyyy must it be a Kardashian!

According to TMZ, Rob has been dating singer, and Rihanna look-a-like Rita Ora since December, and supposedly even got each other's names tattooed on their hands recently.

Speaking of the Kardashians … KIM posted a close-up of her badunk in tight jeans along with the caption, "I think my butt looks too big in these jeans."

Like all women, Kim was probably fishing for compliments more than she was looking for the honest truth, but since she asked: Does Kim's butt look too big in these jeans? Put me down for 'yes'. Like Sir Mixalot, I like big butts and I cannot lie, but these jeans do not flatter Kim's money-maker at all.

COULD BE TRUE, COULD BE CRAP - JENNIFER ANISTON HAVING SHOTGUN WEDDING: Is JENNIFER ANISTON going to have a shotgun wedding? According to the "National Enquirer", Jen's mom is telling people that she's going to be a grandmother, and that her daughter is getting hitched in Mexico soon.

One of those people Jen’s mom allegedly spoke to told the tab, quote, “[Jennifer and Justin Theroux] plan to tie the knot in one of Jen’s favorite vacation locales, a beach in Mexico, and they’re going to do it before the end of the year. Nancy (Jen’s mom) said that Jen doesn’t want to be showing too much on her wedding day.” ‘The Enquirer’ claims that Jennifer wants to speed things up her mom’s health is deteriorating.

TOM CRUISE ALLEGEDLY GOT OFF CHEAP IN DIVORCE FROM KATIE: We'll probably never know the details of TOM CRUISE and KATIE HOLMES' divorce settlement, but that's not going to stop the tabloids and gossip sites from speculating.

TMZ is reporting that Katie did not get a huge payout as many initially believed because there was an ironclad prenup in place. What she will get is $400,000 a year in child support. That's about $33,333 a month, or 4.8 million over the next 12 years.

Which isn’t much when you consider Tom is worth $250 million. Tom and Katie also supposedly agreed that Suri would never go to a “residential school,” meaning she won’t be shipped off to boarding school, whether it’s Scientology or some other type.

BABY POOP - SNOOKI HAS SUCCESSFULLY REPRODUCED: She did it! SNOOKI brought another life into this world yesterday morning. Please welcome Lorenzo Dominic LaValle. This is the first illegitimate child for Snooki and her fiancé Jionni LaValle. Snooki Tweeted, quote, "I am so in love with my son Lorenzo Dominic! I had my little man last night, healthy at 6 pounds!

MORE BABY POOP: ANNA FARIS and her husband CHRIS PRATT became first-time parents sooner than expected on Saturday. Anna gave birth to a baby boy, whom they named Jack. Although everything appears to be fine, Anna's rep noted that Jack was born "earlier than expected", and will be spending some time in the neonatal intensive care unit.

USHER WINS CUSTODY OF HIS SONS: USHER was victorious in his custody battle with ex-wife Tameka Foster. A judge Friday awarded him full custody of the couple’s two sons. Tameka will still have some custodial rights, but it is currently unclear how much she’ll be able to see the kids.

TMZ reports that Tameka plans to appeal, and feels the judge in the case may have been biased, after discovering that Usher’s lawyer’s firm threw a fundraiser for him in 2008.