They're a couple rarely seen in public, together only since February.
So when Academy Award-winning power-couple Charlize Theron and Sean Penn walked in to Dior's Monday show, holding hands and sat prominently on the front row, it's not only the couture gowns that dazzled guests.
France's former First Lady Valerie Trierweiler, meanwhile, took politics to the catwalk, using couture week as a platform to raise awareness for the missing Nigerian schoolgirls in the latest example of red-carpet activism.
Here are highlights of Day Two of the Paris haute couture fall-winter 2014 collections, including show reports from Christian Dior, Giambattista Valli and Schiaparelli.
CHARLIZE THERON AND SEAN PENN
Theron and Penn triggered a frenzy as they arrived together the Paris' Rodin Museum show hand in hand.
Thirty-eight-year-old Theron — a brand ambassador for Dior — wore a gold shimmering fringed cocktail dress similar to the one she appears in for Dior's now-iconic "J'Adore" perfume advert.
She and 53-year-old Penn, who wore a black Dior suit with open shirt, chatted with LVMH boss Bernard Arnault.
That held up the show, but that didn't seem to help another Oscar-winning guest who was running late.
"Hunger Games" star Jennifer Lawrence ended up having to catch a repeat of the show later in the day because her flight was delayed.
DIOR COUTURE'S "FORWARD AND BACK" ENCYCLOPEDIA
"Encyclopedic" sums up Raf Simons' latest adventure for Dior — his most masterful yet.
Set in a circular ballroom catwalk, the Belgian designer ambitiously channeled some four centuries of style — with a fashion-forward twist he called "forward and back."
Simons' journey started with 18th-century dresses fit for an avant-garde Marie Antoinette.
Voluminous exaggerated French ball gowns in pale jacquard silk were made contemporary with trapeze structuring.
The couture novel continued in eight distinct chapters, with guests gasping in delight each time they were transported on to a different era.
There were the long-line coats of Edwardian England — one in dark gray cashmere that gently curved down the body stood out in its deceptive simplicity. Elsewhere, a beaded off-white flapper-style gown shook vibrantly as the model walked.
Then came the famed Bar Jacket of the 1949 "New Look" — represented in this exhaustive 62-piece show by exaggerated collars in black, and one great flappy coat in cobalt blue wool.
But the real stars of the show were the heels.
In deep red, vermilion, pink, black, yellow, orange and cerulean blue, the incredible pointed stilettos, with missing sections in the middle, gave these "forward-and-back" encyclopedic princesses the illusion of the longest legs known in any age.
FORMER FRENCH FIRST LADY USES RED CARPET FOR POLITICS
Former French First Lady Trierweiler broke with tradition — instead of wearing Dior to the Dior show, she wore Paul and Joe.
But there was a good reason: red-carpet activism.
The 49-year-old journalist sported a white T-shirt that read #BringBackOurGirls, a reference to the missing Nigerian schoolgirls who have still not been returned after their April kidnapping. It's the latest example of the growing phenomenon of using celebrity events for a good cause, seen prominently at May's Cannes Film Festival.
"There are 220 missing. It's been two and a half months since these young girls were taken," she said.
In May, First Lady Michelle Obama made the girls an overnight cause celebre when she tweeted an image of herself holding a poster that read #BringBackOurGirls, demanding help for the girls captured by extremist group Boko Haram.
"Two and a half months ago the world spoke about these young girls, including Michelle Obama. But now no one is," she said.
"I'm using the media here to publicize this. Until they're freed I won't stop campaigning," she added.
SCHIAPARELLI'S CONTROLLED ECCENTRICITY
The golden age of Elsa Schiaparelli — the '30s and '40s — were revisited in the second outing for the age-old house, which re-launched last year to mixed reviews.
This season, designer Marco Zanini tried hard to emulate the eccentricity of the house founder, whose business folded following World War II, by mixing up contrasting styles or deceptive material.
He found some success. In a striking look, exaggerated fur shoulders harking from the '40s were pieced on a leopard-print double-breasted coat with tubular sleeves. Glycerin-glazed black ostrich feathers elsewhere made a cool bolero resemble monkey fur.
But the abundant use of embroidery and decorations, like a try-hard clown's hat, made it feel like the talented Zanini was not always at complete ease and made the eccentricity look a tad controlled.
Still, the leopard-print catwalk was great fun.
GIAMBATTISTA VALLI'S STRIPES AND FLOWERS
It was a floral and optical ode to the fifties for Italian designer Valli.
Alongside big bow hair ribbons, retro monochrome stripes plastered vertically, horizontally and diagonally gave energy to loose-fitting sheaths and produced many beautiful plays on transparent tulle skirts.
Flashes of bright colors, like a vivid yellow waist band, gave the retro looks a trendy lift.
It was a strong collection, and the embellished floral embroideries in bright red, blue, pink and yellow across '50s full skirts were some of the best quality seen so far this year.
The Rome-born designer lost his way a little toward the middle of the show with a black-and-white look that evoked Cruella de Vil.
But the show finished on a well-deserved crescendo as the designer came out to receive his applause surrounded by a multicolored army of ethereal, voluminous tulle bridal dresses.
FASHION'S PRESIDENT STEPS DOWN
Didier Grumbach may not be a household name, but the outgoing president of Paris' fashion federation has held an incredible influence on global style over the years.
Grumbach, who has announced he is stepping down, has been credited with revitalizing dying haute couture from behind the scenes and bringing young designers to the fashion world.
Back in the day, as an executive he even helped launch Givenchy and Yves Saint Laurent Rive Gauche.
Speaking to The Associated Press, bespectacled Grumbach reflected on the health of couture today.
"Even 15 years ago, couture could have filed for bankruptcy. Now there's new blood, new designers," he said.
"It's very much alive with brands as strong as Armani and Dior and Versace, a craft that's modern again," he said.
"I have supported younger couture designers because there was a real need. It's the fundamentals of our craft," he said.
After 16 years at the helm of the key trade group, Grumbach is bidding the fashion world goodbye — to be replaced by Ralph Toledano as president of the fashion federation.
Thomas Adamson can be followed at http://Twitter.com/ThomasAdamsonAP