Act The Mellow
It's actually self explanatory.. This phrase, first popularized in the song Mellow by the artist HXBIBTI, means to pretend to be "chill" or "cool" (when you really just want to put yourself out there) just for the sake of a varying numerous reasons. (Ex. for a friend, or even a significant other.) Another variation of this phrase: "actin the mellow"
~ you eight faced shadow, all you should really do is act the mellow. ~