Celebrity Bella Hadid Celebrates Her Older Sister's Birthday Wearing Sexy "Gigi" Swimsuit By Kelsey Glein Kelsey Glein Twitter Kelsey Glein is a Seattle-based writer and editor who covers all things fashion, beauty, and pop culture. She was previously the Digital Editor of InStyle and is currently a Social Media Manager at a cosmetics company. InStyle's editorial guidelines Updated on April 25, 2016 @ 12:15PM Pin Share Tweet Email Photo: Dimitrios Kambouris/Getty Images What better way to pay tribute to your big sister on her birthday than by wearing a swimsuit featuring her name? Bella Hadid did just that to honor Gigi Hadid's monumental 21st over the weekend, showing off her toned physique in a black one-piece that had "Gigi" written across the front in gold lettering. Bella took to Instagram yesterday to show off the sexy suit ($220, brunamalucelli.com) that she donned during a trip to the beach in Malibu, Calif., captioning the picture: "#1 fan." The duo's mom, Yolanda Hadid, also 'grammed the photo and wrote: "Celebrating 'GIGI' day........ @bellahadid #Sisterhood #PointDume." See Gigi Hadid Celebrate Her 21st Birthday Weekend with Her Gorgeous Siblings And it looks like the blonde bombshell had one busy weekend. After kicking off her celebrations with all of her gorgeous siblings and then spending a day at the beach, Gigi headed to Coachella last night with BFF Taylor Swift to watch Calvin Harris perform. Check out more photos from her celebrations—which also included her super hot boyfriend Zayn Malik—below.