Looking ultra casual in matching low-key ensembles, Heidi Montag and Spencer Pratt enjoyed a romantic day together in Malibu, where they did a bit of shopping before relaxing on the beach.

While it seems reality TV's most unpopular couple has been avoiding the spotlight lately, they're actually hard at work on more serious projects!

Montag has been busy writing a "tell all" book, while Pratt has re-enrolled at the University of Southern California to finally complete his degree.

Find out what grade one of Hollywood's "most hated" men earned on his last term paper, after the jump ...

Twinsies!

Sisters Hilary and Haylie Duff donned matching workout gear (that made us do a double take!) as they headed to a Pilates and Piloxing class in LA, on Thursday.

The mommy-to-be has been working extra hard at maintaining her fitness since becoming preg, and it's definitely paying off, because she looks fabulous!

Duff was lucky enough to attend an exclusive private dinner party held for President Obama, when he paid a visit to LA early this week.

The actress Tweeted on Monday: "Wow just had the most interesting dinner with about 20 couples and @BarackObama !!Always fascinating to talk to such influential people!".

Is it too late to change costumes?

Reformed wild child Nicole Richie has made a public plea to girls everywhere asking them not to "dress slutty" for Halloween this year.

The 30-year-old mamma of two posted on her Facebook page Thursday:

"Girls, can we all pledge that we will not dress slutty for this Halloween? The jig is up!"

Ever since Richie married Joel Madden and became mom to Harlow, 3, and Sparrow, 2, she dresses much more conservatively, and has kept her Halloween costumes very "G" rated.

Last year Richie went as Jessie from Toy Story, in 2010 she went as Margot Tenanbaum from The Royal Tenanbaums, and in 2009 she kept it covered up as the White Rabbit from Alice in Wonderland.

A pregnant Jennifer Garner and hubby Ben Affleck went on a lunch date today, and not only did the happy couple hold hands after their meal, but they also sported matching blue outfits. Awww, think Jen they planned this?

Ben is currently directing and starring in Argo, so it must be nice to spend time with his wifey on a day off from shooting. After Argo wraps, he's set to begin production on a Whitey Bulger biopic with buddy Matt Damon, so it looks like Jen's going to be on her own again for a while!

And she manages to make an otherwise ugly umbrella look oh so chic!

Eva Longoria was snapped in New York City on Thursday evening, and despite the crummy weather, the 36-year-old starlet looked like a knockout when we caught her leaving a meeting at Warner Bros. Hmm, think she's looking to get into another TV series? With Desperate Housewives coming to an end early next year, she'll definitely be back on the market for a new gig, so we'd love to see her stay on the small screen!

In other news, it was recently reported that Eva told gal pal Jessica Simpson not to get married on November 11, 2011, perhaps due to the fact that her own marriage crumbled just three years after she walked down the aisle on July 7, 2007. So what did Eva have to say about that? "Wow, some dumb magazine is reporting I told Jessica Simpson to cancel her wedding date because I'm superstitious! So not true!" she tweeted today. "My denial is at end of story but they ran it anyway. Makes no sense how they can lie to the public. #annoying."

Only two months after getting married (and less than a year since meeting each other), newlyweds Kim Kardashian, 31, and Kris Humphries, 26, have been in the middle of a firestorm in recent weeks over alleged problems within their marriage.

Allegations include that Kris has been flirting with other women, that Kim is angry over his lack of work ethic and that the relationship was fake from the start -- the result of a casting choice from E! to give Kim a relationship on her reality show, Keeping Up With The Kardashians.

Both have remained silent on talk of problems, but Kim just spoke to People, and she didn't deny that the couple are having issues.

Kardashian blames NYC for the marital woes; the couple moved there right after getting married to film the upcoming season of Kourtney & Kim Take New York.

"It's not ideal because you're newlyweds and you want privacy," Kim said. The couple lived with Kim's sister, Kourtney Kardashian, her boyfriend, Scott Disick and their son, Mason.

Kim's mother and "momager" Kris Jenner defended the couple, saying they have been going in "two separate directions [with work]," but that "they'll figure it out as soon as they get back [to L.A.]."

Kim and Kris got back to Los Angeles earlier this week.

Reese Witherspoon stopped by Fred Segal in Santa Monica after hitting the gym this morning, and the Oscar winner left the store with a bag full of goodies and a slight smile on her face.

Aside from her usual routine of shopping and sweating it out in spandex, it appears as though Reese may have a new job offer on the table. According to Deadline, Sony has reached out to both Reese and funnyman Jason Segel to star in a movie called Sex Tape, which follows a married couple who "spice up their sex life by making a dirty home video, only for the tape to disappear." It already sounds hilarious!

Chaz Bono was spotted leaving Anderson Cooper's NYC studio today, and we already have a sneak peek at the interview, which airs next Tuesday.

The two phoned Chaz's mom Cher, and she shares her thoughts on his elimination from this week's Dancing with the Stars. Judge Bruno Toniolo called Chaz a "fluffy penguin" when judging him on Monday, and Cher sputtered:

"I just thought they [the judges] were rude and it was gratuitous rudeness. I was just p***ed off. I was really upset. Not that Chaz was voted off but that they were so disrespectful."

Cher also spoke out regarding Chaz's decision to become a transgender.

"As a mom, you have a child and then all of a sudden, you have a different child, but you have the same child. So it's very hard to kind of twist your mind around to the adjustment. But then when you look at it, and you're around your child, you just think, 'Oh, no difference.' Same child, different wrapping."

Watch the video clip after the jump!