What WE expect is for these ladies to look perfect ... and they certainly do!

Jennifer Lopez, Cameron Diaz and Brooklyn Decker were decked out to the nines while they worked the red carpet at the premiere for their new movie What To Expect When You're Expecting.

We have to admit that JLo really put Cam's dress to shame. The sexy 42-year-old Latina sizzled in a floor length and flowy Maria Lucia Hohan Gown. She paired her dress with Sergio Rossi shoes and jewelry by Jacqueline Nerguizian.

Ms. Diaz played it safe in a short and semi-sheer black knitted dress ... showing off her incredibly sexy bod. Cute, but a little too understated if you ask us.

Brooklyn Decker chose a Giambatista Valli dress and jewelry by Blue Nile jewels. The perfect choice, indeed!

See all of the stars who hit the red carpet in our gallery below.

Cameron Diaz and friends hit the red carpet for the premiere of What To Expect When You're Expecting at the AMC Lincoln Square Theater in NYC last night and suffice to say, everyone looked stunning at the star-studded event!

Diaz, along with her leading ladies Brooklyn Decker and Elizabeth Banks, looked absolutely astounding in their outfits with smiles to match while the men of the film didn't look too shabby themselves.

Check out the pics in our gallery to see the rest of the cast and more!

What To Expect When You're Expecting hits theaters May 18.

Their movie What To Expect When You're Expecting hits theaters on May 18, and now co-stars Jennifer Lopez and Cameron Diaz are dishing their thoughts on parenting in the June issue of Redbook magazine.

J.Lo admits to experiencing the "baby blues" after giving birth to twins Max and Emme, now 4. "I remember after the babies were born, about seven to 10 days in I was like, 'What is going on with me?' the American Idol judge reveals. "I felt sad and depressed and thought the babies didn't love me."

After reading up on the hormonal drops new mothers experience, Jenny from the Block realized that her depression was directly correlated to childbirth and has since developed a rock solid bond with her babies with ex Marc Anthony. TV host, singer, actress, mogul, mom... what a multi-tasking mama!

Cameron Diaz, on the other hand, chose her career over starting a family, and has no regrets about her decision.

"I thought I was going to be married and have two children by the time I was 21. I think I felt I had to model after my mother's. But then my career was starting to take off and there was still so many things I wanted to do. So that dream for me was shattered very early on. After that I never put another timeline on anything in my life," the 39-year-old actress explains to the mag.

We applaud the Bad Teacher star for calling her own shots, but we secretly hope she decides to take on motherhood in the years to come. We think a little Cammie would be the cutest thing ever! Plus, now that her bestie Drew Barrymore is expecting, maybe Miss Diaz will catch baby fever?

Cameron Diaz misses her long hair .... big time!

While visiting The Tonight Show with Jay Leno, the What to Expect When You're Expecting star shared her regrets about her recent haircut.

The 39-year-old actress tells Leno:

"There was a little misunderstanding. I said I just wanted a little bit cut off and it went from here to here. It was one of those moments where I just couldn't ... I just burst into tears."

We think she can pull off that short 'do! Cam adds, "I felt so vulnerable. For a woman to all of a sudden have no hair ... oh my God!"

Diaz turns 40 soon! Talk about sexy at any age.

Tom Munro/Harper's Bazaar

Cameron Diaz covers the June issue of Harper's Bazaar UK, and the 39-year-old actress chats about her famous friends and her love for the city (and the men!) of London.

Cameron and the reporter spent three hours together at Gemma, a restaurant next to the Bowery Hotel in NYC, and the mag says the ladies drank a bottle of wine before, during and after their interview. Party on!

On her relationship with fellow actress Gwyneth Paltrow, Cam says, "We became very close after my dad’s death. She reached out and it was very sweet. We bonded on that." When asked about her Gambit co-star Colin Firth, she gushes, "He’s the perfect Englishman. Just enough of the self-effacing to a point that it’s comfortable for other people, but also totally charming and engaging to where he makes you feel special. He’s got that British honesty.”

And speaking of British men, Cam says, “I love their sense of humor and the sense of chivalry and charm. It’s something that is innately a part of the culture – we don’t have that over here, it’s not the same in America." Think Cam will go for a British beau next? She's not exactly attached to anyone at the moment!

I guess we can add these two to the list of friendliest Hollywood exes!

Alex Rodriguez and Cameron Diaz dated on and off for over a year, and even though their relationship fizzled, their admiration for each other never waned. The Yankees slugger and the What To Expect When You're Expecting actress enjoyed a hot and heavy romance, and it seems the leggy blonde beauty left quite the impression on the notorious lothario.

"I don't like talking about my relationships, but I will tell you about CD: She's probably one of the greatest human beings I've ever met, and just an amazing light," the baseball star reveals to The Insider.

In case it wasn't clear, "CD" is the Dominican athlete's nickname for his former love. Aww!

A-Rod is currently dating WWE superstar Torrie Wilson, but that doesn't mean he's ready to settle down! When asked if he considers remarrying in the future, he explains, "I'm not sure. I think my new hero is George Clooney. He is my role model. I think he's done it right."

One word of advice ladies - if you want a ring, don't let your man hang out with Gorgeous George!

Cameron Diaz sure seemed to look bright-eyed and bushy tailed upon her arrival back in LA!

The actress, who donned a striking white blazer, scarf and flip flops, arrived at LAX last night carrying her own luggage after a brief vacay in Kauai, Hawaii. The Shrek star has been filming her latest movie, What To Expect When You're Expecting, alongside Jennifer Lopez and will undoubtedly hit the road once more to promote the rom-com.

For someone who's been living in their suitcase recently, she sure looks good doing it!

Maybe Cameron Diaz should consider joining Dancing with the Stars for real!

The Bad Teacher star showed off her flawless figure -- and amazing dance moves! -- in a sexy sequined bikini in a new trailer for the upcoming flick, What to Expect When You're Expecting.

Diaz can be seen performing a flawless salsa dance with costar Matthew Morrison for Celebrity Dance Factor, a fictional DWTS-esq show that will be a part of the upcoming movie, which also features X Factor's Cheryl Cole as a judge, and Whitney Port as a dancing contestant.

What To Expect is based on the pregnancy guide book of the same name, and centers on a collection of stories about different women who are preg. The film also costars Jennifer Lopez, Chris Rock, Dennis Quaid, Elizabeth Banks, Brooklyn Decker, Chris Rock, Anna Kendrick and Chace Crawford, and hits theaters May 18.

Work it, girl!

Lion's Gate