MDMA (3,4-methylenedioxy-methamphetamine or ‘ecstasy’) is well-known for its empathic and sociable effects (Bogt, Engels, Hibbel & Van Wel, 2002). Indeed, there is a body of work that discusses the role the drug plays in social bonding (Beck & Rosenbaum, 1998; Duff, 2008; Farrugia, 2015; Hinchliff, 2001; Solowij, Hall & Lee, 1992). However, there has been extremely limited research looking at MDMA’s impact specifically on romantic relationships (Vervaeke & Korf, 2006). Hence, this thesis explored couples’ experiences of intimacy on MDMA and how this intertwines with their relationship. Semi-structured interviews with ten couples, using visual methods (Reavey, 2011; Del Busso, 2009; Majumdar, 2011), and eight individual written diaries (Kenten, 2010) were analysed using a thematic approach (Braun & Clarke, 2006). A ‘bubble’ (Sloterdijk, 1999 cited in Klauser, 2010) is argued to organically form around couples on MDMA, producing a distinct affective atmosphere of muted fear, worry and shame and heightened feelings of safety and love, which mediates emotional and discursive ‘practices’ of intimacy (Gabb & Fink, 2015). Movement, spaces and objects are also argued to facilitate intimacy, producing new subjectivities which alter boundaries: between self and world; within the self; and between self and other (Brown & Stenner, 2009). Yet beneath the seeming ‘flow’ to MDMA experiences, couples construct clear, symbolic boundaries, segmenting these experiences from both everyday life (Douglas, 2001), and other people (Stenner, 2013). The research is argued to have key implications for drug theory and practice, namely that drug use is not only an individual act (Duff, 2008) but also relational in nature – its meaning partly determined by how it interweaves with important relationships in people’s lives.