The 28-year-old reality star spent time with the 31-year-rapper Monday, as seen in video clips French Montana shared on social media.
"@robkardashian get ready !!!!" he captioned a video of himself and Rob goofing around.
Khloe and French Montana first dated in 2014 and appeared to temporarily reconcile last spring. The rapper had nothing but good things to say about the 31-year-old reality star when he spoke to E! News at the Grammy Awards in February.
"She's good, she's good," he said of Khloe. "I spoke to her last week. We're great friends. I think we're going to be friends forever."
Khloe was linked to French Montana again after her split from NBA star James Harden last month. The reality star dismissed reconciliation rumors by re-tweeting, "Just because two people who were involved are seen together, doesn't mean they're back together."
Rob and French Montana's friendly get-together follows news the reality star will move into a new, $2.3 million house. Some speculate his girlfriend, Blac Chyna, will also be moving in, and sources told Us Weekly the two are interested in their own reality show.
"They're talking about doing their own reality show," an insider revealed. "E! would be hesitant about a spinoff, [though]. They'd need to see him film on Keeping Up [with the Kardashians] first."
"[Rob's mom] Kris Jenner would totally get behind [Blac Chyna also joining Keeping Up]," the source added. "If it takes Blac Chyna to help Rob rejoin life, Kris will be on board."
Rob and Blac Chyna have been linked since January, and some credit the 27-year-old model with improving Rob's health by helping him to lose weight. The reality star gained 100 pounds in the past few years and had largely retreated from the spotlight.