Sylvester Stallone and his brood were living it up on the French Rivera … making everyone who’s not there extremely jealous.

Sly, along with Jennifer Flavin and his 3 daughters Sistine, Sophia and Scarlet, were the picture of beauty on yacht.  Kinda goes without saying the women gorgeous.  That’s 21-year-old Sophia is in the copper-colored metallic bikini … as they say in the law — res ipsa loquitur.  Look it up.  

Stallone just wrapped Creed II” … and the buzz is good.