Social wearables promise to augment and enhance social interactions. However, despite two decades of HCI research on wearables, we are yet to see widespread adoption of social wearables into everyday life. More in-situ investigations into the social dynamics and cultural practices afforded by wearing interactive technology are needed to understand the drivers and barriers to adoption. To this end, we study social wearables in the context of Nordic student culture and the students' practice of adorning boiler suits. Through a co-creation process, we designed Digi Merkki, a personalised interactive clothing patch. In a two-week elicitation diary study, we captured how 16 students adopted Digi Merkki into their social practices. We found that Digi Merkki afforded a variety of social interaction strategies, including sharing, spamming, and stealing pictures, which supported meaning-making and community-building. Based on our findings, we articulate Memetic Expression as a strong concept for designing social wearables.