Well, it looks like it's true!
And on Thursday, the 28-year-old reality TV star decided to flaunt the fact as he snapped a pic from the gym and posted it to Instagram.
While you can't see his face, it's clear the tatted guy on the bench press is the one and only Rob.
So, who could be taking the snap??
You can just make out someone's refection in the mirror and we have a good guess it's his new flame, considering the two are getting their workouts in together.
It's good to see the youngest Kardashian sibling taking care of himself.
[Image via Instagram.]