For those wondering about her pre-party routine, the new mom (who welcomed son Jack in August 2024) kicked off her birthday with what she called a “bday burn” workout session with trainer Kirsty Godson, proving that even birthday girls don’t skip leg day. Which, of course, makes plenty of sense when you’re going pants optional!

Hailey Bieber celebrated her 28th birthday in style on Friday night, surrounded by her friends as she wowed in an all-black get-up. See details.