The family had been enjoying lunch at celebrity hotspot The Ivy on Sunday, 26 July, when they were surrounded by admirers wanting a picture.
Showing he's a perfect gent, music exec Corey kept an arm around Kourtney as he led her back to their car.
Or perhaps he was just making sure she didn't trip in those oversized, super long trousers?!
Corey's been dating Kourtney's mum Kris since last year. It's believed they first met via mutual friends at a party in Ibiza last summer. He's been pictured out with the family on numerous occasions, suggesting he gets on really well with Kris' many kids.
Kourtney, meanwhile, has been dealing with the aftermath of her split from longtime partner Scott Disick, the father of her three children.
She's kept silent about the separation, but numerous reports claim the final straw came when she saw photos of Scott looking cosy with another woman in Monte Carlo, while she was at home in LA with the kids.
Scott broke his silence on the situation at the weekend, telling reporters via Us Weekly: "[I'm] just taking it one day at a time. With everything going on right now, I need to be positive for myself."
It's been reported that Kourtney has already spoken with family lawyers and is requesting joint custody so their children can have both parents in their lives. They're parents to sons Mason, five, and seven-month-old Reign, and three-year-old daughter Penelope.
All you need to know about Kourtney Kardashian: