Pippa Middleton is enjoying a Lake Como vacation ahead of her 40th birthday.

Pippa, who is Kate Middleton's younger sister, was seen in a striped bikini, taking a dip in a pool right beside the lake.

She was in the prestigious Italian vacation hot spot to celebrate the wedding of London-based influencer Annabelle "Belle" Porter and Max Robinson.

Pippa Middleton stripped bikini

Pippa Middleton in a striped bikini during Italian vacation. (Backgrid)

The mother of three put her toned physique on display poolside. She was first seen in a striped bikini and later changed into a baby-pink bikini. 

PIPPA MIDDLETON FLAUNTS BIKINI BODY 11 WEEKS AFTER GIVING BIRTH

Pippa — who turns 40 on Wednesday — and her billionaire husband, James Matthews, share three children: Arthur, 4, Grace, 2 and Rose, 1.

Pippa and her beau, a financier, began dating in 2012 and said "I do" in 2017. 

Pippa Middleton pink bikini

Pippa Middleton enjoyed a dip in the pool ahead of her 40th birthday. (Backgrid)

In a blog post for Waitrose magazine, Pippa revealed that swimming helped her during pregnancy.

"Swimming throughout pregnancy offers a wonderful feeling of weightlessness," she told the outlet.

"As the months pass, you feel heavier by the day, but being in water gives that floating, light-as-air feeling that soothes and relieves the body, counteracts increased back strain and stretches the legs from the growing bump. It’s non-impact, gentle and relaxing," Pippa concluded.

Pippa and Kate Middleton

Pippa Middleton is the younger sister of Kate Middleton. (Max Mumby/Indigo)

In 2019, Pippa revealed that her son, Arthur, was already fond of swimming when he was just six months old.

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"Starting my son, Arthur, swimming at four months old has given him confidence and enjoyment in water," she told Waitrose at the time. "He’s now six months old, and swimming is one of our favorite activities. The exercise helps guarantee sound daytime sleeps, and the movement has improved his digestion."

Pippa rose to fame in 2011 when millions around the world watched her serve as Middleton’s maid of honor at the royal wedding. She wore a figure-hugging gown for the occasion that quickly went viral. The moment also sparked completely unfounded rumors that she was dating Prince Harry.

Pippa Middleton and husband James Matthews

Pippa Middleton and James Matthews tied the knot in 2017. (Mark Cuthbert/UK Press via Getty Images)

She is notoriously private and rarely gives interviews, but Pippa has written a book about entertaining and columns for Vanity Fair while also working at her parents’ lucrative "Party Pieces" business.

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Back in 2016, sources told People that Pippa had "a deep desire" to disappear from the spotlight and live a quiet life while raising her children.