Also at the show was Bella's ex The Weeknd, who performed the show's finale.
The Weeknd hasn't been shy about running around with his new flame Selena Gomez, making the whole situation extremely awkward for the model.
In fact, Bella has said part of her will always love the musician, and that she didn't trust Gomez's intentions. She apparently felt the "Can't Keep My Hands To Myself" singer was using him.
Thankfully, Gigi was there to give her sister some support when they walked past the performance.
It probably doesn't help Selena Gomez flew out to spend time with The Weeknd in Paris as well.
PARIS AKA THE CITY OF LOVE.
Bella and The Weeknd broke up in November after dating for a year and a half, but the singer moved on very quickly with his new girlfriend.
It didn't take long for the couple to announce they were together by making out from behind a dumpster.
But if there's one thing siblings are good for, it's that constant support when you need it the most -- and to silence that internal scream when you see your ex out in public.
The look was subtle and so quick you could have missed it.
The two held hands while they walked down the runway together.
This is a lot like what happens when I go through a breakup. My brother and I will strut down a runway before we are quickly tackled by security.
Our look of internal screams aren't over lost loves, however. They're over how much the security guard's Tasers hurt.
A sibling really is the greatest gift a parent can give you.