Academic and policy discourse has idealised academic mobility despite studies showing that it can have adverse effects on individuals' experiences and contribute towards exacerbating existing inequalities. This article focuses on career (im)mobility stories of science, technology, engineering and mathematics (STEM) early career researchers that are variously sticky with emotion and affect. It places emphasis on the challenges, frictions and emotional tensions for early career researchers as part of this decision-making, irrespective of whether they decide to move or not. To do this, it deploys the concept of stickiness, which allows investigating the intersection and co-construction of embodied experiences of early career academics with the internationalisation discourse of academic excellence which are not often brought together. Focused on a largely under-examined population and context, it is based on a qualitative analysis of 15 in-depth interviews with a subsample of survey respondents, as part of a mixed methods study of Greek researchers in STEM. This article compares two groups of early career researchers who are seemingly at odds but have a lot in common: those with a highly international outlook moving to build an international profile and those who decide to stay and pursue research aspirations within a national context. Stickiness is demonstrated in two ways: stickiness to establishing an international profile and an academic career dictated by the internationalisation discourse; stickiness to affective considerations which are temporal, fluid and often understated. The main difference is how early career researchers address this stickiness: through the normative international mobility or participation in collaborative funding programmes. This article shows academic mobility is not only associated with benefits but can entail negative implications for individuals. It also provides empirical insights into hidden STEM early career researchers and elaborates a concept of stickiness in academic (im)mobility with discursive and affective layers, highlighting the importance of considering affect in career development scholarship.