"They are officially boyfriend and girlfriend," a source told the publication.
"He's a gentleman, has very old school manners and treats her well. He is also very health conscious and they've been motivating each other with their health journeys."
Rebel made their romance Insta-official at the end of September when she shared a snap of the pair boarding a helicopter alongside fellow Hollywood heavyweights Helen Mirren and Kate Beckinsale.
The group were en route to attend the Planetary Health Gala, as well as a private dinner with Prince Albert.
“Quick Helen, get to the chopper! #TeamMonaco,” she captioned it.
Lately, however, Rebel and Jacob have been packing on the PDA, sharing loads of photos and commenting on each other’s social media posts.
“Great to be back home 💕 and back to work 💕” Rebel wrote alongside a selfie from the weekend prompting Jacob to respond with, “Beautiful.”
Too darn cute!
Below, we’ve rounded up a few more moments that prove they are meant to be!
Jacob was previously linked to former Real Housewives of Beverly Hills star Adrienne Maloof, who is 25 years his senior.