<p>The end of a long-term romantic relationship ranks among the most stressful and momentous events in life. Thus, the decision of whether to break up with someone whom one has been with for many years should generally be made very carefully. Unfortunately, decision theory is often thought to be unable to provide rational guidance in such high-stake life choices due to the outcomes’ presumed transformative character. The present paper shows how agents can rationally decide whether to leave their romantic partner <i>even if</i> the decision is transformative. It does so by using a novel five-level account of transformative decision-making, which can also be used for other key life choices, and which is the first to integrate in a systematic way several approaches for making (certain types of) transformative decisions that have been proposed in recent years.</p>