Kourtney Kardashian has been tied to Justin Bieber for months, but when it comes to her happiness, the Keeping Up With the Kardashians star is all about her children.

Weeks after a report claimed Kardashian and Bieber were continuing to hook up in Los Angeles, the reality star and mother of three shared a photo of herself and her youngest son, Reign.

Along with her ex-boyfriend, Scott Disick, Kardashian is mom to three children, Mason, 6, Penelope, 3, and Reign, 1. And while Kardashian has reportedly moved on from their nine-year relationship with Bieber, Disick has been spotted with numerous models, most of whom are quite young.

“They might be over but it is still weird to see the father of your children make out with someone else,” a source told Hollywood Life last week. “Especially someone so young. It kind of has been creeping Kourtney out.”

But does she really have room to talk? While 32-year-old Disick may be spending time with women in their 20s, Kardashian and Bieber have a 15-year age gap between them.

Kardashian and Bieber "hooking up on and off for a few months now," a source told PEOPLE Magazine in April, revealing their romance began last year. 

"They have hooked up a few times, including recently. It happens in L.A," the source explained. "He has met her kids, but they don't hook up around the kids. It's on nights when she has help and is able to go out."

"Kourtney is great. Justin thinks it's cool that she is older and hot. She isn't clingy and has her own life," the source continued. "There are no bad consequences for Justin to hook up with her. She is very easy going and just makes it fun for him to be around her.”

For more Kourtney Kardashian, tune into Keeping Up With the Kardashians Season 12 on Sunday nights at 9 p.m. on the E! Network and for more on her relationship with Bieber, check out the clip below.

Tags: kourtney kardashian scott disick Justin Bieber