Kourtney Kardashian, Megan Fox Team Up for Sexy SKIMS Shoot with Apple

Kourtney Kardashian and Megan Fox are taking their FIRST bite of an apple together -- as in, simultaneously -- and they're doing it for Kourt's sis. Anything for family!!!

The duo -- whose BFs, Travis Barker and MGK are tight -- are featured in a new promo for SKIMS's Cotton collection, rocking the line's Jersey Dipped Thong and the Jersey Triangle Bralette. We doubt many of you are looking at the clothing, though, because Meg and Kourt are abs-to-abs and one red apple away from locking lips.

Photog Donna Trope's hot shot seemingly confirms these 2 are now tied at the hip, beyond just their guys.

In fact, Kourtney and Megan shared some screen time just over a week ago at the VMAs -- where they threw to their boos' joint performance ... calling them "our future baby daddies."

There've been other outings among the quartet -- but this really cements their bond.

As for how exactly it came to be ... we're hearing it was all Kim's doing, who thought it'd be a fun and creative way to showcase her collection. Also, these 2 ladies are absolute smoke shows -- and a get-together like this is sure to get people talking. Go figure, right?