Khloé Kardashian Teases Rob for Flirting with Natti Natasha on Twitter: 'Who Is This Girl?'

Khloé Kardashian has always been protective of her family — so her interest in Rob Kardashian‘s latest potential fling is no surprise.

Rob, 32, has been flirting up a storm with Dominican singer Natti Natasha on Twitter. On Sunday, one of their exchanges caught Khloé’s attention, so she called her brother out.

“Rob what’s going on here?!?! Who is this girl?” she tweeted, responding to Rob’s tweet that he’d be seeing Natasha, 32, “soon” after she wished him a happy Father’s Day.

“Do I know you?” he jokingly responded.

“Don’t make me pop up on your a—,” his sister teased.

“Listen just slow yourself down I’m trying to watch the Dodgers game,” Rob wrote.

“Coming over then,” replied Khloé, 34. “I’ll see you soon.”

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Rob’s flirtation with Natasha follows his tumultuous relationship with ex-fiancée Blac Chyna. The two started dating in early 2016, and the relationship caused major friction with his famous family, given her contentious history with his sisters.

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By February 2017, PEOPLE confirmed that two had called off their engagement, and the relationship only went downhill from there, with both alleging abuse in separate lawsuits. Most recently, the two appear to be in a better place as they co-parent their 2-year-old daughter Dream, although they’ve disagreed over whether the child can appear on Chyna’s new docu-series.

And while Rob has struggled with weight gain and depression in recent years, retreating almost entirely from the public eye, he appears to be working on himself and revealed on Monday that he was back in the gym.