ABSTRACT By using unique elite interviews, this paper examines municipal level politicians’ decisions about whether or not to govern with the Sweden Democrats. In the 2018 election, the Sweden Democrats were electorally successful in many municipalities but only participated in governing a handful. Considering office-, vote- and policy-seeking aspirations as key determinants for party behaviour, this study finds that such decisions are primarily driven by policy-seeking objectives. The study further establishes the importance of a factor seldom explored in coalition research, suggesting that social relations substantially affect (non)cooperation with the party. This contribution holds imperative value for future research on political party behaviour at the local level, emphasising the necessity for future scholars to not directly apply theories developed for the national level to the local level. The analysis also unfolds this possibly vague concept, conceiving of social relations as a matter of; (dis)satisfaction, (in)appropriate behaviour, (dis)trust, (un)familiarity, and leadership.