Appearing on the late night host's "Spill Your Guts or Fill Your Guts" segment -- where celebrities either answer an invasive question or eat a disgusting delicacy -- he was asked to rank wife Hailey Bieber's famous friends "from your favorite to your least favorite."
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The singer put Jenner first, then Hadid, then Delevingne, explaining that he knew Kendall the best and hadn't spent a lot of time with either of the other women. "I have nothing against those people. It's not like I'm like, 'Screw Cara!'" he explained. "I don't want to eat a bull's penis. It is what it is."
Delevingne shared a snipped of the segment to her Instagram page on Friday morning, along with two throwback photos of her with Justin in happier times.
"Now vs. Then," she captioned the post. "If you have nothing against me, then why don't you unblock me? Love you @haileybieber - he should have just eaten the bull penis."
Her girlfriend, Ashley Benson, clearly got a kick out of the post, writing "😭🤣" in the comments.
While Bieber does follow Kendall on Instagram, he doesn't follow Cara or the Hadids. There's no way of knowing whether he blocked Delevingne, who is following Hailey, but not Justin.
This isn't the first time Cara has called out Justin on social media. After Bieber shared a lengthy post criticizing Taylor Swift for going after Scooter Braun for purchasing her masters in July 2019, Cara went in on Justin in the comments. She also hit back at Hailey calling Justin a "gentleman" for his post.
"Gentleman? @haileybieber @justinbieber you must be bored," Delevingne wrote at the time. "I wish you spent less time sticking up for men and more time trying to understand women and respecting their valid reactions."
"As a married man, you should be lifting women up instead of tearing them down because you are threatened," she continued. "I am not sure you actually understand what an apology is. This issue that @taylorswift is talking out is about far more than a picture and you know that. As you said, you haven't spoken to her in years, which means you definitely don't understand the situation. I do."
"Take a step back and try and learn from this," she added. "We should all be on the same team. End of story."