The song "Your Motherfucker" by Mondo Cozmo is about wanting to be everything to someone in a relationship. The singer expresses a desire to be their partner's rock star idols like Elvis Presley and Mick Jagger, their caregiver like a doctor, their protector like a father, and their confidante like a girlfriend or lover. They want to be the one that their partner turns to in times of need and the one they can't live without. The repeated use of the term "Your motherfucker" throughout the song emphasizes the strong emotional connection and intensity of the relationship. It conveys a sense of possessiveness and devotion, as if the singer is declaring themselves as the one and only for their partner. Ultimately, the song captures the intensity and passion of a relationship where one person wants to be everything to the other, willing to be their rock, their comfort, and their everything. It's a raw and emotional expression of love and longing in a modern, gritty American way.