Ashton Kutcher and Mila Kunis Celebrate Wilmer Valderrama's Birthday 

More Food More Pets More Red Carpet More TV Watch More Unfiltered More Country

Carrie Underwood: I Need to \'Lock Down\' a Baby Name Soon

Which Oscar-Winning Actress Used to Cheer Up Prince Charles?

David Beckham on His Kids: \'I\'m Literally an Uber Driver Now\' (VIDEO)

Prince Harry Wants Prince George to Run a Marathon (He\'s Only Joking)

New Book Makes Surprising Claims About Prince Charles\'s Household

Bobbi Kristina Brown Still \'Unresponsive,\' According to Source

Bruce Jenner\'s Family All Support His Transition Decision, Says Source

Justin Timberlake Confirms Jessica Biel\'s Pregnancy – See the Sweet Photo

Ashton Kutcher and Mila Kunis Celebrate Wilmer Valderrama\'s Birthday

Ashton Kutcher and fiancée Mila Kunis joined Valderrama at Palms Thai restaurant in Hollywood on Jan. 29 to celebrate their former costar\'s 35th birthday.

When Valderrama arrived, he was surprised by the large group of friends there to join him.

"He was laughing and saying that he had expected a quiet dinner," a source tells PEOPLE.

Kutcher, 36, and Kunis, 31, "looked cute" as they shared a family-style Thai dinner and enjoyed drinks throughout the evening.

When it came time to sing "Happy Birthday," Valderrama\'s girlfriend Demi Lovato, who planned the surprise party, presented the birthday boy with a personalized cake.

IT\'S MY #BIRTHDAY!!!! Haha!! I was surprised last night by all the people I love!! I felt so blessed! I love you! pic.twitter.com/URMw7rfoPV

“They clapped and cheered when Wilmer blew out the candles,” the source says of the new parents. "They acted very down to earth."

After Valderrama blew out the candles, Kutcher led the guests in a rendition of "For He\'s a Jolly Good Fellow."

"Ashton and Mila looked cute," the source says. "They seemed to have the best time."

MORE ON: Ashton Kutcher , Demi Lovato , Mila Kunis

Croatian Model Stabs Identical Twin Sister Over a Guy

Why Was Cindy Crawford \'Very Nervous\' to Work with Sofia Vergara?

Take an Exclusive Look Behind the Scenes of Carrie Underwood\'s New Video

Please enable JavaScript to view the comments powered by Disqus.

Prince Harry, Plus Colin Firth, Leonardo DiCaprio & More!

The Celebrity Guide to Sharing Your Baby News

For Bobbi Kristina Brown, Minutes Without Air \'Could Be Grim\'

Everything Super Bowl: Celebs, News, Ads & More!

Viola Davis Uses a Very Surprising Food Product as Her Red Carpet Secret Weapon

Save Your Pennies: Girl Scouts Are Raising Cookie Prices

Do Bobbi Kristina\'s Social Media Accounts Hold Clues About What Happened?

Why Maksim Chmerkovskiy and Kirstie Alley Aren\'t Speaking

Chris Pratt Flashed Amy Poehler?! Hear His Take – And See Her Reaction

Thank you for signing up! Your request may take up to one week to be processed.