Rihanna's New Year's Day seems like it was perfection -- wearing a tiny bikini while hanging out in St. Barts with a bunch of friends.

Which do you think bothers Bethenny Frankel's soon-to-be ex-husband more -- seeing her amazing body in a tiny bikini ... or that she's rocking it with her new man?

Frankel spent the day of New Year's Eve on the beach in Miami with new beau Michael Cerussi. Bethenny's daughter with estranged hubby Jason Hoppy is reportedly with the couple on the trip.

As if all this wasn't enough to irk Hoppy -- whose divorce from Bethenny is still not quite final -- Frankel tweeted, "NYE day & i'm exactly where i want to be with exactly who I want to be with."

It's a tale of two parents -- while Heidi Klum frolicked around topless in St. Barts with her boyfriend Vito Schnabel ... Seal took their kids to Mammoth for a ski vacation.

Heidi's moguls are the best around.

Salma Hayek is not one to flaunt her curves -- we rarely see her rocking little black bikinis -- which is why we're showing you these pics of her ... rocking a little black bikini.

Salma was yachting in St. Barts with her husband Francois-Henri Pinault over the holiday weekend.

Kris Jenner is through watching all of her daughters strip down and bare it all ... the 59-year-old clearly wants in on the action ... and the result is weird as hell.

Kris and Kendall Jenner won't be breaking the Internet anytime soon with this bizarre vid shot for LOVE Magazine's advent calendar ... it's a head-scratcher for sure.

When you're done eyeballing her long-legged 19-year-old daughter check out how a robotic Kris comes off like the sad mom embarrassing her kids at a sleepover.

Well ... at least they don't make out.

Take a look.

Vanessa Bryant takes her Christmas card photo VERY SERIOUSLY -- so seriously in fact that Mrs. Mamba tapped one of the top designers from "Project Runway" to make her dress.

Kobe Bryant's wife called upon MTCostello -- who has designed clothes for huge stars like Beyonce and Ariana Grande.

They got together and picked out MTCostello's signature "Black Widow" gown -- which comes with a $6,500 price tag!!

Vanessa had flirted with a bronze version of the dress during an earlier fitting ... but ultimately, decided to go with black.

Sources close to the situation tell us ... Vanessa has always been passionate about Xmas cards. As one person put it, "She takes great pride and puts great thought into celebrating because she's very religious."

Steven Spielberg is always ready for his close up!

Here's a 39-year-old version of the "Goonies" god at an old school Hollywood event back in 1985 (left) and nearly 30 years later ... the movie making mogul -- who celebrated his 68th birthday earlier this week -- at a fancy Washington D.C. party earlier this month (right).

The 1980s are long over and Milwaukee Bucks forward Jared Dudley says NBA players have evolved ... and now they shave their armpits.

Jared apparently solved a life-long mystery for our photog when he left 1Oak Thursday night ... because our guy was just DYING to know if the NBA made players shave ... or if it was a choice.

Dudley said that shaving was the thing to do these days ... unlike the Patrick Ewing days of yore.

Conrad Murray's locked up and loving it -- he's grown his hair out so long that he's gone next level ... the man bun.

Michael Jackson's doc enjoyed a lunch date Thursday in Miami with his gf Nicole Alvarez.

Take a look as we tie up the top 10 top knots!

8. Leonardo DiCaprio

Britney Spears looks ... different on the cover of Women's Health Magazine, and while many people suspect a Photoshop job -- TMZ has obtained video that shows that's probably not the case.

Sources involved with the photoshoot tell TMZ ... Britney's facial changes can be attributed to a makeup technique called "contouring" ... which accounts for her slimmer nose and more defined cheek bones.

Check out the video ... she looks exactly the same on set as she does in print.

It really is Britney, bitch.

2:50 PM PT --  Kim just copped to the photo edit ... tweeting, "Wait is this really news that I posted a selfie & cropped my daughter out? LOL … Her eyes were closed and I was feeling my look! Can I live?!?!"

Kim Kardashian doesn't like to share the spotlight with anyone, even her own daughter.

KK posted a selfie Sunday night that rather conspicuously cuts off the face of North West ... and the move did not go unnoticed.

Comments on the photo from some of Kim's 23 million followers included:

-- "Seriously you can't even let your own child in a picture with you #selfishness"
-- "Lmao if she loved her child she wouldnt have cropped out the pic"
-- "Narcissism at it's finest"
-- "crop game strongggg, poor North your mom would rather showoff a brick wall than you.....SHAME!!!"

In all fairness, that is a lovely wall.

Mike Vick is like the black Paul Mitchell .. 'cause his black hair brush business is KILLING IT ... with demand for his WaveMasterz products higher than ever ... TMZ Sports has learned.

We broke the story ... Vick and Bow Wow got involved with the company last year after falling in love with the brushes.

Vick ended up buying 40% of the company. Bow Wow got 10%.

And the investment is paying off in a big way ... with WaveMasterz telling us the company is shipping out more than 500,000 brushes this holiday season to keep up with demand.

We're told the company only shipped out 3,000 last year ... when the company was in its infancy.

We spoke with Vick who tells us he's ecstatic about the growth -- saying, "I love the WaveMasterz brush ... it’s why I wanted to do more than endorse the brush, but be a part of this company."

He adds, "Now, we have to make sure the production keeps up with the demand because the response, even as we launch has been amazing."

Karrueche Tran is a single woman -- at least until she gets back together with Chris Brown for the umpteenth time -- but in the meantime, she's flaunting her single body all over Miami.

It's not hard to see why Chris kept going back.