Hot Mamas

She's 23 years OLDER than Miley Cyrus ... but Jennifer Lopez was out to prove she's the real TWERKING QUEEN during a booty-bouncing performance in Miami.

JLo and her big 'ol butt hit the stage at the "iHeartRadio Ultimate Pool Party" on the CW last night ... and threw her glutes around like a 44-year-old CHAMP during her new aptly-named hit, "Booty."

So, the real question ... how do Ms. Lopez's twerk skills match up with 21-year-old Miley??

What's the greater miracle ... an astronaut getting pregnant after spending a year alone in space ("Extant" ... coming soon!) ... or Halle Berry's nipple somehow popping out of a dress that seemingly appears nip-slip proof?

Jennifer Lopez contorted her body into all sorts of positions this weekend ... rehearsing before her gig at the iHeartRadio Ultimate Pool Party in Miami.

Jenny McCarthy's looks have never been let go.

Here's the then 23-year-old "Singled Out" host at the MTV Movie Awards in L.A. back in 1995 (left) and 19 years later -- the now 41-year-old "The View" outcast at an NYC party earlier this year (right).

Khloe and Kim Kardashian were in a horse race Friday night ... each clearly trying to take the evening with assets that are undeniably spectacular.

Khloe and French Montana got nice and cuddly sailing on the Utopia III in NYC on the Hudson River ... to celebrate K.K.'s 30th birthday ... and her incredible ass clearly made some partiers go full mast.

And then there's Kim ... whose boobs could save perhaps a dozen lives in a nautical emergency.

Oh yeah ...Kris, Kylie and Kendall Jenner were there too.

Now that's a party we could get behind.

Courteney Cox just turned 50.

Hillary Clinton's looks are a facial filibuster!

Here's the then 44-year-old soon-to-be First Lady posing for a photo in Los Angeles back in 1991 (left) and 23 years later -- the now 66-year-old former Secretary of State speaking at an event in New York City earlier this year (right).

Her beauty secrets are classified information!

Jennifer Lopez takes her security very seriously ... because today in New York, she strolled all of 30 feet flanked by a TEAM of security that acted like it was escorting the president.

JLo was leaving an office building Thursday afternoon when our photog tried to ask her about the anti-paparazzi clause in her divorce settlement with Marc Anthony.

But her team -- at least 3 bodyguards and 2 handlers -- had ALL sides (even that one) covered ... making it clear NO ONE gets close to JLo.

With their equally legendary backsides already enshrined in the Hall of Fame, Kim Kardashian and Jennifer Lopez each wore outfits on Monday that showed off their commonly overshadowed cleavage.

First we have Kim (left) in New York City after having dinner with her sister Kourtney, and then J.Lo (right) appearing on 'The Tonight Show.'

The question is ...

According to reports ... Kanye stuck to his normal schtick during the gig -- ranting about how he wants to become a timeless icon like Walt Disney and Shakespeare.

Will Smith and Jada Pinkett Smith took their tight, toned bodies to the beach today in Hawaii -- proving once again ... Jada is the hottest 42-year-old mom in a 2-piece.

Mr. & Mrs. Smith had something for everyone -- her toned ass barely covered in a bikini ... and his ripped arms in a tank top.

If you're impressed -- you're not alone. 13-year-old Willow was there too ... and looked pretty awestruck by her parents' ridiculous physiques.

Will still rules in Summertime.

A wobbly Jessica Simpson hit up Warwick nightclub in Hollywood Sunday night, but from the looks of it ... she did plenty of partying beforehand -- and even had to make a 911 call for fast food to soak up the booze.

Simpson was accompanied by Eric Johnson and it's a good thing he was there ... because somebody had to make sure she didn't fall flat on her face!

Mrs. Weight Watchers -- who did look AMAZING -- had a hard time making her way in and out and definitely seemed to have a hard time answering fairly simple questions. Best part of the video ... the driver making a Jack in the Box run for Jessica WHILE she was in the club!

Jennifer Lopez did her first ever concert in her hometown of the Bronx last night, and she did not hold back the goods ... giving the crowd a view of her prized backside.

J.Lo's free show at Orchard Beach -- in advance of her new album coming out later this month -- featured actual singing and multiple costume changes ... most of which showed off her rear end, thankfully.

The butt show was clearly a response to the latest challenger to the ass throne ... Bradley Cooper.

Reese Witherspoon's been a lot more fun lately ... The Proof? Let's just say, 24 proof.

Reese let loose Saturday night, looking pretty tipsy as she got on stage to sing "Jackson" with Kenny Chesney ... and she paid a pretty penny for the duet.

Maybe nostalgia prompted her to drop $24,000 for Drew Brees' foundation at a bash hosted by Matthew McConaughey. In return she got to sing at the House of Blues in New Orleans.

Reese swayed and shimmied in a white lace dress, and even pretended to pick at her teeth -- real country style.

After warbling the first few notes she hit her stride ... then faltered again.

Kim flashed her engagement ring for photogs ... and then she gave 'em the same rearview wedding guests will see walking down the aisle -- and it's glorious.

Jennifer Lopez and her mother were cruising through Manhattan when it happened -- our camera guy got the magical shot that proves Jenny from the block ... is also a chip off the ole one.

And Mama Lopez has all the proof (and junk) we need (in her trunk).