Hilary Duff, Mike Comrie Throw Son Luca 3rd Birthday Party After Divorce Filing: Photos

Going hard for Luca's 3rd birthday. ???? @hilaryduff

A photo posted by haylieduff (@haylieduff) on Mar 21, 2015 at 2:47pm PDT

Focusing on their little Luca! Just one month after filing for divorce, Hilary Duff and her estranged husband Mike Comrie threw an adorable 3rd birthday party for their son on Saturday, Mar. 21. The exes — who announced their separation in January 2014 — were joined by family and friends for the outdoor bash.

Cutest Dad-to-be & Dad around! @mattyrose3 & Mikey ????

A photo posted by haylieduff (@haylieduff) on Mar 21, 2015 at 4:22pm PDT

One attendee in particular couldn't stop gushing about Hilary's baby boy — Haylie Duff. Luca's aunt, who is expecting a baby girl with fiancé Matt Rosenberg, documented the day's events via Instagram.

Happy birthday to the little man! I can't believe your baby is already 3!!! @hilaryduff

A photo posted by haylieduff (@haylieduff) on Mar 20, 2015 at 9:16am PDT

The pregnant actress-turned-chef posted throwback photos of her nephew, and indulged in vanilla cupcakes with sister Hilary. "Going hard for Luca's 3rd birthday," she joked. Hilary showed off her new turquoise-colored hair while celebrating, and wore a cat mask on top of her head. Comrie, meanwhile, wore an elephant one.

"Cutest Dad-to-be & Dad around! @mattyrose3 & Mikey," Haylie, 30, captioned another photo. The men helped out by carrying in a large cake inspired by the 2006 animated film Cars.

Duff, 27, and the former NHL player, 34, may have officially called it quits, but they appear as amicable as ever — and upbeat.

You know #yolo and all that ????

A photo posted by Hilary Duff (@hilaryduff) on Mar 22, 2015 at 11:09am PDT

"3 years buddy! 3 beautiful years! You make every minute worth while! We cherish all your firsts and all that is to come," Duff captioned a photo of their son Luca on Friday, Mar. 20, appearing to reference Comrie. "Happy 3rd birthday my love #timesflying #whatayear."

Hours after the party, she also posted a selfie and showed a glimpse of her gold "Luca" bracelet. "You know #yolo and all that," she quipped.

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