Over 100 million people are affected by suicide loss every year. Descriptive and qualitative research describes the consequences of this loss, such as elevated health risks, as well as describing experiences that can potentially lead to resilience for suicide loss survivors (SLS). The facts that suicide loss is highly transformative, and that it affects many people, underscore the need to understand the relationship dynamics leading up to suicide loss. This study aims to explore relational dynamics between suicide victims and the involved SLS in suicidal trajectories that end in death, through examining the SLS lived experiences. The study is designed and conducted through a phenomenological, reflective lifeworld approach. Twenty-two in-depth interviews concerning SLS's lived experiences of suicidality that ended in a loved one's death by suicide were conducted. This study formulates how the relationship between the suicide victims and the SLS in a suicidal trajectory are shaped around the dynamics of 'May I', 'Will I' and 'Why', and explores how living through these concurrent phases creates a suicidal death course. A central finding indicates that suicidality is often shared between the suicide victims and the SLS, and another is that there exists a determinate dynamic of negotiation aiming for a mutual understanding of the intention to die. The essence of an interpersonal relationship in a suicidal trajectory can be understood as 'an implicit negotiation in which a shared understanding of the intention to die is reached'. This study gives scientific support to the conclusion that SLS may have important information through their own experiences that can be of value for suicide care and assessment.