They're so cute together!

On Saturday, Heidi Klum and her boyfriend Martin Kristen were all dressed up in workout gear while displaying some sweet PDA on the streets on New York City.

The 40-year-old model and her man put those workout clothes to good use as they jogged throughout the city and performed some leg-strengthening exercises.

A couple that sweats together stays together!

Heidi Klum's family is as adorable as it gets.

The model and her large brood looked elated as they lunched at Toscana in Brentwood, then shopped at City Zero in Westwood. Heidi was smiling ear-to-ear while holding hands with daughter Lou and later linking up with the entire clan as they crossed the street in a line. Her bodyguard-turned-beau Martin Kristen seems to have made the perfect addition to her beautiful family.

Leni, Henry, Johan, and Lou later shared a big hug with their mom before seeing her off at LAX. Parting is such sweet sorrow!

It's hard to believe that ageless beauty Heidi Klum is actually 40 years old.

The model celebrated her big 4-0 on Saturday with a hat-themed party in Culver City. Heidi's bodyguard-turned-beau Martin Kristen and her children Lou, Henry, and Johan attended the party, which was thrown by one of Heidi's friends. Real Housewives of Beverly Hills star Yolanda Foster was also in attendance.

Her adorable children dressed according to the theme, donning derby and Panama hats for the occasion. Lou was the only one who chose not to sport a lid, instead letting her wild mane flow free.

Klum took to Twitter earlier that day to show her children's thoughtful gift: painted molds of their tiny hands.

I'm 40! Look what I got from my 4 beautiful children. Thanks everyone for all the wishes, flowers, balloons & gifts twitter.com/heidiklum/stat…

— Heidi Klum (@heidiklum) June 1, 2013

She also posted a photo of her party, where she wore a gigantic three-piece top hat. Check it out after the jump.

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Heidi Klum and Sharon Stone were white hot in Cannes Friday night at the amFAR Gala. The dress code called for colorless clothing, but Heidi liked the look so much, she wore white to the Nebraska premiere as well.

Check out all the stunning looks in our gallery!

Love is most definitely in the air.

Heidi Klum and her bodyguard-turned-boyfriend Martin Kristen hit the beach in Malibu on Saturday after a hike in the Hollywood Hills and Martin couldn't keep his hands off her ... stomach. The lovebirds lounged in the sand and watched Heidi's children play in the water, periodically sneaking in belly rubs, kisses, and hugs.

The new America's Got Talent judge, who was dressed in a flowy striped black and white halter, looked completely at ease during the outing. At one point, she wrapped her arms around Martin from behind while resting her head on his back.

However, Martin's hand placement on his girlfriend's belly was a bit peculiar. He was probably just resting his hand or showing affection, but there's also the possibility that Heidi's pregnant with baby number five. She's already mom to Leni from ex-boyfriend Flavio Briatore and Henry, Johan, and Lou from ex-husband Seal. At least we know the baby would be born into a loving household.

She pulls off the bright look quite well!

Heidi Klum showed off her colorful style in a sunny yellow shirt and matching shoes with boyfriend Martin Kristen as they cheered on her kids at a soccer game in Brentwood on Saturday.

The 39-year-old model and mother has been a mainstay at the weekend games with her bunch, which can affectionately be considered "soccer Saturdays" now.

Gotta love her dedication!

She makes traveling look sexy!

Heidi Klum caught a flight out of LAX airport last night, and the model decided to dress for comfort in black pants, flats, and a velvet jacket, but she still looked stunning!

The German stunner has been busy with America's Got Talent, but she still found time to relax and unwind last weekend. The blonde beauty tweeted the below photo, which showed off her amazing body, with the caption, "Happy Mother's Day! Best Mother's Day ever..."

We love that she enjoys the finer things in life, like drinking wine while lounging in the pool!

From supermodel to supermom!

Heidi Klum spent the day before Mother's Day with her beautiful brood. She took her daughter Leni and three of her adorable friends, who sported matching brightly colored sequined tanks, ra-ra skirts, and bike shorts, to a soccer game. The girls and Heidi's boyfriend Martin Kristen watched from the sidelines and cheered on as Heidi's boys Johan and Henry played soccer.

After hanging out at the park in Brentwood, the gang headed to Santa Monica for some more fun in the sun. The kids and their soccer buds biked around the beach before going to Venice's famous Muscle Beach to play with exercise equipment.

Heidi recently told Us Weekly that it's difficult to balance her busy professional life and her personal life. After giving the interview, she added America's Got Talent judging duties to her already heavy load.

"It's a huge responsibility to have four kids," she said. "They all have different likes and dislikes and activities that they want to do. You have to learn how to juggle all of that, and at the same time, give them each the love that they need. ... When you have one [child], you can focus on one. With four, you have to make sure [your attention] is all spread out just right. You have to understand how different they all are! And at the end of the day, there is not much time left for you!"

She certainly found activities for them to do on Saturday.