The song is about a woman cheating with her best friend's boyfriend[1] and was released digitally on 1 March 2019 as the fifth single from Shark's debut studio album Love Monster.

[2] At the Queensland Music Awards 2020 "Mess Her Up" won Highest Selling Single.

[4] The video was co-directed by David O'Donohue and Shark with a narrative following a complicated love story.

Shark said: "It was important for me to be involved in the process as I was the one who came up with the concept of these two worlds that play out through the video.

The video was produced by Felicity Jayn Heath and shot in Los Angeles.