Bella, 19, and Scott, 33, were snapped kissing and snuggling on Wednesday in Cannes, France, and a source close to Kourtney Kardashian's ex tells ET that although the unexpected pair is "hooking up," it's all just fun.
"They're just hooking up. It's nothing serious," the source says. "They have known each other for a while now."
Interestingly enough, Bella has been friendly with the Kardashian-Jenner clan since her Disney days. She posed with 19-year-old Kylie Jenner and 21-year-old Kendall Jenner at a Popstar! Magazine party all the way back in December 2011.
Bella is definitely closest to Kylie. The two were spotted having lunch in Los Angeles together a year later in December 2012, and were still pals by April 2013, when Kylie tweeted a picture of the two making silly faces for the camera.
"Love you! @bellathorne," Kylie wrote.
The pair looked all grown up in September 2015, when they were seated together front row at the Vera Wang Spring 2016 show during New York Fashion Week and happily posed for a photo.
Check out Bella giving Kylie a kiss on the cheek.
Bella even gushed about Kylie during an interview with HuffPost Live in December 2015. "I love Kylie, she's super sweet," she said. "Kylie and I don't really get to hang out all that much, we used to hang out more often when we were both a little bit younger. She's so sweet ... We have lots of mutual friends."
And last March, Bella jumped in to defend Kim Kardashian West during the 36-year-old reality superstar's public feud with Chloe Moretz over Kim's nude Instagram photos.