Jennifer Lopez did a quick change in Paris today, slipping out of the little white dress she wore to this morning's Chanel show and into a flirty pink dress to check out Valentino. J Lo brought her daughter, Emme, and boyfriend, Casper Smart, along to see Chanel, though for Valentino's midday Paris Fashion Week presentation, she arrived holding hands with just Casper. The pair sat in the front row, next to the designer himself, and got a close look at the Spring 2013 Valentino designs as they came down the runway. Afterward, J Lo returned to her hotel to pick up her son, Max. J Lo and her gang are currently touring Europe as part of her Dance Again world tour. Following their quick stop in France, they're jetting back to Portugal for a show in Lisbon before moving on to Spain, Ireland, Russia, the UK, and Turkey.

Kristin Cavallari made her way through security at LAX last night with her son, Camden Cutler. She had her hands full with a stroller, baby essentials, and her new dark gray Hermès Birkin bag that was a push present from her fiancé, Jay Cutler. Baby Camden isn't yet 2 months old, but he's already becoming a pro at traveling. Kristin's been in LA for the past week shooting her upcoming Chinese Laundry footwear campaign, as well as making a cameo on FX's The League.

Kristin and Camden caught an outbound flight from LA to NYC, while Jay and the Chicago Bears put on a solid show defeating the Dallas Cowboys 34-18 in Texas. Jay's been catching some heat for his on-field antics, and last night was no different. He was spotted blowing off the Bears' offensive coordinator, Mike Tice, but following the game, Cutler laughed off the sideline incident, saying, "You guys have got to sell papers and it's hard out there. But we can't blow up every headline. Things happen in football games. Just because I walk off and go get water, that doesn't mean much."

Cameron Diaz celebrated her big 40th birthday in August, and just a few weeks before marking the milestone, she posed for Esquire UK — her full interview appears in the November issue, which goes on sale Thursday, Oct. 4, on newsstands and digitally. Cameron got sexy in lingerie for photographer Terry Richardson and touches on getting older, marriage, and kids in the publication. Here's more from Cameron Diaz in Esquire:

• On getting older: "There's no such thing as anti-aging — it's all a crock of sh*t, you can't go back in time. So for me, it's about living in this moment, the best that I can. Contentment is about coming to terms with life as it is, rather than getting all pissed off that things didn't fit into your little prescribed box. And it's much bigger. For the first time in my life I'm content. I'm so excited. Getting older is the best part of life. Like, I know more than I've ever known. I have gratitude. I know myself better. I feel more capable than ever. And as far as the physicality of it — I feel better at 40 than I did at 25."
• On marriage: "It just wasn't the thing I was drawn to. I certainly didn't want it in my twenties. Or my thirties. And I'm going to be 40 in three weeks. So we'll see! I'd always wanted to get hitched in Vegas at least three times. It's funny because as my girlfriends get older, I see how their relationships have evolved, and you know, the people you're drawn to changes. I'm not attracted to the same people that I was drawn to in my twenties."
• On having kids: "I don't need to have the children in my life be a part of my literal flesh. And anyway, there's still a possibility of that, I aint that old. Believe it or not, I'm feeling very...capable."

Photos courtesy Terry Richardson for Esquire UK

Natalie Portman and Benjamin Millepied took Aleph for an evening walk in Austin, TX, yesterday. The family of three stopped on the Congress Avenue Bridge, which houses one of the world's largest urban bat colonies. Thousands of bats fly out from under the bridge and across Lady Bird Lake at dusk, and Benjamin captured the show on his camera. Natalie is in Texas with her boys to film an untitled Terrence Malick movie. Her costars Ryan Gosling and Rooney Mara have already been in front of the cameras. Ryan took a break from work over the weekend, though, to spend time with his mom.

Jessica Biel had a busy one in LA yesterday. She wore wide-leg pants to shop with a friend, then hung out at home and spent time in the kitchen. She tweeted, "Back home and back in the kitchen. Big debate this Monday — banana bread vs. cupcakes. Thoughts?" Jessica ended up making a cinnamon banana bread. Later on, Jessica flashed her huge engagement ring from fiancé Justin Timberlake as she took the wheel of her car and headed home following a night out with friends in West Hollywood.

Jessica returned to LA after a recent trip to Illinois, where she cheered on JT at the Ryder Cup Captains & Celebrity Scramble at Medinah Country Club. Justin's been doing a fair amount of traveling as well — he jetted to Mexico in mid-September for his bachelor party! JT and Jessica, who got engaged over the holidays in 2011, are prepping to finally tie the knot. They're rumored to be heading to Italy in the coming weeks for a ceremony at Francis Ford Coppola's Palazzo Margherita.