Kourtney Kardashian and Kylie Jenner Hang with Rob’s Ex Adrienne Bailon

Reunited and they feel so good.

Kourtney Kardashian and Kylie Jenner hung out with Adrienne Bailon — their brother Rob’s ex-girlfriend — and flaunted it all over Instagram. The photos show the trio posing together, with smiles from ear to ear. However, it’s the captions that may or may not be throwing some shade at Rob.

Kylie captioned her snap, “cause we are sistersss” (a reference to a Cheetah Girls song), and Kourtney simply wrote, “Reunited best friends lol.” If this is their way of shading him (after what he posted to his Instagram this week), it’s quite good just because of the history here. In case you didn’t know, Rob and Adrienne dated for two years before breaking up in 2009.

Reunited best friends lol.

A photo posted by Kourtney Kardashian (@kourtneykardash) on

cause we are sistersss 🎶 A photo posted by King Kylie (@kyliejenner) on

This rekindled friendship also comes after Rob started dating Blac Chyna — who is Kylie’s boyfriend Tyga’s baby mama. It doesn’t get more complicated than that, does it?