The former 3LW and Cheetah Girl star dated Kim Kardashian's brother for two years before parting ways in 2009, and although she is no longer in touch with her ex, she is still good pals with his sisters.

Adrienne enjoyed a night out with Kourtney and Kylie Jenner in Los Angeles last weekend (27-28Feb16), and it was clear from the ladies' social media posts their friendship is firmly in tact.

Kylie shared a photo of the trio having some fun and captioned it, "Cause we are sistersss (sic)," while Kourtney added another picture on her Instagram profile and wrote, "Reunited best friends lol (laugh out loud)."

Adrienne, who appeared on a number of previous episodes of Keeping Up with the Kardashians, has now opened up about their bond, insisting she is "absolutely" on good terms with the reality TV family.

"I think when people saw the photo people were like, 'What's happening?'" she explained to UsMagazine.com "But you're just catching up, does that make sense? So we are, we're cool."

"It's always great to see them," she added. "I think they're amazing girls. I think they'll always be a part of my life!"

Rob famously confessed his infidelity caused his break up from Adrienne during a 2010 instalment of Keeping Up with the Kardashians.

However, the 32-year-old beauty holds nothing against Rob and she recently insisted she was glad he had started dating again after embarking on a romance with Kim's former friend, Blac Chyna.

"He deserves happiness, so I'm happy for him," she told Us Weekly. "He seems happy. He's a great guy. I always say that. We were in love at one point, and I think when you're younger, what is that, hindsight is 20/20? You look back, and you're just like, 'We were young and in love,' and life goes on. You wish that person the best. You always wish well on people."

Rob's new romance hasn't been without controversy as Blac shares a three-year-old son with rapper Tyga, who is now dating 18-year-old Kylie. The awkward relationship drama has reportedly driven a wedge between Rob and his family, but he has made it clear he is not about to dump model Blac, who he has since moved in with.

He also hit back at all of his critics with a fiery Instagram post on Thursday (03Mar16), when he shared an image of Blac sleeping on a couch.

"Love this woman right here so f**k y'all with your negative comments‼️," he wrote.