It's not like she can ask Scott Disick to do it!

Kourtney Kardashian braved the rain in LA yesterday to take son Mason to a doctor's appointment, and the reality star was looking mighty skinny in spandex workout pants. It sounds like she's doing everything she can to keep it right and tight for The Biebs!

"Kourtney is getting more and more obsessed with her looks since hooking up with Justin. He’s only 21 and has perfect skin and a flawless fat-free body. Kourtney is working out like never before, making sure she’s super skinny,” a source dished to Hollywood Life.“She also won’t let Justin see her without make up on," the source added.

It's like she's totally forgotten about her estranged baby daddy!

Speaking of The Lord, new reports claim the father-of-three is invited to Kris Jenner's annual Christmas Eve bash, but it's still unclear if he will attend. The whole Kardashian clan opens presents Christmas morning at Kourt's Calabasas mansion, so we bet LD will make that for the sake of his kids.

"This year, we have definitely downsized the party. Because I think the older we get, and with all of us being so busy, it's more important to spend the holidays with our immediate family and really close friends. We always do Christmas morning at Kourt's, and all of our presents are under her tree. We head over in our pajamas when we wake up—it's such a fun tradition!" Kimmy K explained recently on her website.

It would be Kris Jenner's dream if JB joined the celebrations!