AceShowbiz -

Kim Kardashian can't hide her jealousy of Kourtney Kardashian's super fit figure. "Kim's extremely jealous of Kourtney's bikini body, don't get me wrong she's proud of her, but she still can't help feel like she's losing some sort of competition," says a source close to the reality star.

The source tells HollywoodLife.com that Kim and Kourtney have always been this competitive. "When they were kids they would compete over every little thing and not much has changed," the source further explains.

However, the "Keeping Up with the Kardashians" star fortunately knows how to beat Kourtney's body as well as working out her feelings. "She's back training hard with Gunnar and she's still workout of with Don too." Kim is very determined with her working out plan as she wants to get in better shape than Kourtney.

Kim previously received backlash over her unedited photos which featured cellulite on her perky derriere. The mother of two "is still struggling with what happened on their girls trip, the body shaming she got was horrific and she still hasn't totally recovered." However, with her determination to beat Kourtney's bikini bod by working out twice a day, it seems like Kim doesn't have to worry about body shaming ever again.