Selena Gomez & Cara Delevingne Let's Be Friends

7/22/2014 8:29 AM PDT

Cara Delevingne & Selena Gomez: Friends?!? -- Let's Be BFFs

Notorious friender Cara Delevingne has a new gal pal ... Selena Gomez, who celebrated her 22nd birthday with Delevingne aboard a yacht in St. Tropez.

Forget posing for a pic with model Tanz Watson, if Selena really wants to make Justin Bieber jealous ... this is how you do it.