The song "Not My Ex" by Jessie J delves into the experiences and emotions surrounding a past toxic relationship and the journey towards healing and finding love again. In the lyrics, Jessie J reflects on her past relationship where her ex would compliment her but also deceive and hurt her. She blames herself for the pain she endured and questions her worth. However, she realizes that the new person in her life is different and should not be judged based on her past experiences. She acknowledges that opening up and giving her heart to someone new may not be easy due to the scars of her past. Yet, she is willing to take the risk and go along with the ride. Despite her troubled nature, she wants the new person to remember that she is not like her ex and she deserves to be loved genuinely. The song highlights the contrast between the toxic traits of her ex, such as being selfish, controlling, and dishonest, with the healthier dynamics of her current relationship. She assures her new partner that she won't intentionally hurt them, and they won't fall into the same patterns as her past relationship. Overall, "Not My Ex" is a declaration of self-worth, growth, and the desire for a healthier and more fulfilling relationship. It serves as a reminder that everyone deserves to be treated with love and respect, and should not be judged based on the actions of past partners.