Together, the stars looked undeniably bootylicious, drawing attention to their enviable posteriors. J.Lo, 44, paraded around her unbelievably toned calves and bumpin' behind in a form-fitting sleeveless white minidress by Zuhair Murad.
Her sexy counterpart, 26, struck a more coy pose in her racy, sheer black gown that revealed her talked-about thighs and long legs.
J.Lo shared an Instagram pic of the two backstage early Friday morning and wrote, "congrats mama," to the Barbadian-born beauty.
While they have yet to collaborate on a track, RiRi and J.Lo have teamed up -- vocally-speaking -- on DreamWorks' upcoming animated movie, Home. Lopez will play the mother of Rihanna's teenage character Tip.
The animated comedy will be released November 26.