This paper presents emotional and affective labour as invisible designing required to nurture social relationships in participatory practices. Participatory Design (PD) is often framed through visible acts of designing, such as envisioning, co-creating and prototyping. Yet little is shared of the emotional and affective labour and its association with design that enables the condition of safe and comfortable participation. Initiating, nurturing and sustaining social relationships requires ongoing long-term commitment and care that extends beyond acknowledged practices of designing. Examples of emotional labour required for participatory practice are illustrated here through reflecting on our experience in infrastructuring an online transcultural peer mentoring programme for socially-engaged women creatives working in four Asia-Pacific countries. By making these invisible acts explicit, we hope to prompt collective consciousness of the labour involved in structuring social relationships and to support PD practitioners to acknowledge and account for this work in their practice.<p></p>