Directed by Austin Simkins, the video is a big summer mood, as it shows the pair twerking poolside, soaking up the West Coast rays, and cruising the Los Angeles streets with the top down.
"My favorite scene from the music video is the pool scene because me and Rubi were in sync," Day told Complex. "I love the scene where we both stick our tongues out that was fire ... Linking up work Rubi was really great, real positive energy, real positive vibes."
The song comes nearly four months after Day shared her "Mascara" single via Epic Records and YG's 4Hunnid label. Day explained she wrote the song after receiving some hate at the beginning of her career.
"At the time, I was going through a lot of things with people who were jealous or haters, that combined with the beat inspired me to make big,' she said, before touching on her experience working with Murda Beatz. "Considering me and Murda didn’t meet face to face, our first song together is pretty fire."
You can watch the official "BIG" video above. Day is now working on her first full-length project, which she says is "coming soon." Stay tuned.