Celebrity Butts

Kevin Federline's first rap track in 9 years goes deep into the Hollywood scene -- and by deep we mean Kanye West's ass and Amber Rose's fingers.

The song's called "Hollywood" and the music video stars a fake 'Ye and fake Amber, umm ... working out their finger issues (lube included). It also features a parody of Leonardo DiCaprio sweating out the Oscars.

The track itself is a collabo with rapper Crichy Crich (of Tara Reid tattoo fame). Sources connected to the rap duo tell us their intent wasn't to mock Yeezus or Leo ... they were just reacting to what was hot on social media when they shot the video.

Taylor Swift's ass will NOT be contained -- the thing has been busting out lately, and looks great, but also looks, ummm ... different.

Taylor's lady lumps were majorly on display at the iHeartRadio Awards over the weekend as she showed up in a skintight black bodysuit. We did some deep research, checking out a bunch of Taylor butt shots from the last year ... and she's definitely shown some growth.

Butt pads? Squats? Who knows?

Matthew McConaughey's wife is more than a showstopper ... she's straight up breaking necks.

Kourtney Kardashian left only a teeny bit to the imagination with a faraway shot followed by a closeup of her extremely hot crossed buns.

Kourt spent Sunday snapping ass-tastic poolside selfies alongside BFF Sarah Howard. The kids must have been with Scott.

Lil Boosie is doing a victory lap in Hawaii after beating cancer ... and it involves a whole lot of ass.

Boosie hit the surf with a bunch of women and did his best Rihanna impression. Tide was low but Boosie's spirit was definitely high.

As we previously reported ... doctors removed half of his kidney in December after they found cancer.

Appears his close brush with death has made him appreciate life ... and ass more.

Yanet Garcia, aka world's sexiest weatherwoman, is coming to her own defense denying her most famous asset got bigger overnight because of new implants.

Yanet tells TMZ she hasn't had any work done on her trunk as many of her fans -- she has 1.6 million on Instagram alone -- believed after she posted a clip of herself doing her weather thing in a tight black dress.

Yanet is chalking up the rumors to camera angles, which she's definitely a pro at working to her advantage.

If her butt did get bigger Yanet says it's because she exercises regularly. #GirlsWhoSquat

Jennifer Lawrence has a message for the people watching her go.

J Law enjoyed the perfect 80 degree winter temps in LA Sunday ... strolling with a pal in hipsterville neighborhood, Echo Park.

Gigi Hadid's outfit at the S.I. Swimsuit Issue party left little to the imagination, except this -- we can't imagine where the hell her butt went!

Put out an A.P.B. because Gigi's much beloved ass was definitely missing at the NYC event. We're gonna chalk this up to really, really bad camera angles ... even though the profile shot isn't all that cheeky either.

Let's just remember better days -- Gigi's ass at last year's Tommy Hilfiger show ...

The chick whose giant ass made it on one of Kanye West's 'Life of Pablo' covers owes a HUGE thank you to Kim Kardashian for picking her cakes out of a lineup.

The model's name is Sheniz Halil ... and she's already got a pretty solid following online ... not hard to see why.

Sources close to Kanye tell us 'Ye wanted Kim involved in his new album so he let her pick the butt model. As they say ... do what you know, and Kim knows ass.

We're told his art team put a bunch of photos in front of Kim and she picked Sheniz simply because she thought she had the best butt.

Thankfully, Kanye didn't question his wife's prowess.

Blac Chyna should not be Rob Kardashian's first pick to pitch his sock line ... because the distractions are overwhelming.

Chyna posted this pic, wearing little else butt a pair of Rob's Arthur George socks.

Meanwhile, back at the ranch, Amber Rose posted a video with the caption,"Drunk af #trinidadcarnival."

They're still in Trindad ... they like to party.

Blac Chyna, Gwyneth Paltrow and Amber Rose have never hung out in the same place -- far as we know -- but they're all hanging out in the right way this week.

All 3 showed off their differently sized, but equally impressive butts recently, so we have to ask ...

Gwyneth Paltrow defies 43 years on earth ... especially from the rear.

Gwyn basked in the sun during a photo shoot in Malibu -- a day after squaring off in court with her alleged stalker.

The entire island of Trinidad is waking up with an ass hangover -- courtesy of Amber Rose and Blac Chyna's awesome Carnival appearance.

The BFFs were front and center for parades all day and night, and fans captured the action from ALL angles. But one was more popular than others ... obviously.

Ass Wednesday, indeed.

Amber Rose and Blac Chyna are twinning in Trinidad where the Carnival celebrations are looking bigger than ever.

The ladies proudly displayed their assets while hosting one of the many parties going down on the Caribbean island.

We can tell you what the men of Trinidad are NOT giving up for Lent!

Ronda Rousey slapped on a new coat of paint -- a very thin one -- for a new S.I. swimsuit photo shoot in the Bahamas.

The ex-champ's clearly getting used to being naked, essentially, in front of strangers -- and, truth be told, we're getting used to it too.

This is round 2 for Ronda in body paint. TMZ Sports got the first shots of her spread 3 weeks ago on Petite Martinique.

"Teen Mom 2" star Kailyn Lowry took her brand new doctor sculpted butt out for a spin, and her first order of biz was scarfing down some greasy fries and frozen cocktails.

Fresh out of a recovery room -- Kailyn hit up Columbus Restaurant in Miami Beach. She must be feeling confident about diet choices after Dr. Miami shifted her fat cells around to give her a Brazilian butt lift.

Hmm ... this is definitely one way to enhance her surgical enhancements.

#GymsAreOverrated