Background: Despite growing awareness of sustainability, the popularity of ultra-fast fashion businesses continues to grow rapidly. The foundation of this research lies in the inconsistency between consumers' awareness of sustainability and their purchasing behaviour toward unsustainable brands such as SHEIN. This study explores the motives that drive consumers to continue buying and how they justify their actions.

Purpose: The purpose of this study is to explore the underlying factors that motivate consumers to purchase at SHEIN even when in most cases they are aware of the lack of sustainable practices within the business. While also exploring the ways consumers justify their purchases and reasons for changing their actions afterwards.

Method: Using the Theory of Planned Behaviour to explore motives that influence behaviour and Cognitive dissonance to understand how consumers reconcile inconsistencies between their belief and behaviours. This provides a holistic approach to the consumer buying decision process. Conducting 27 in-depth interviews with students at Jönköping University who had purchased from SHEIN. The research reveals the roles of attitude, subjective norms and perceived behavioural control shaping purchasing behaviour. As well as how individuals resolve Cognitive dissonance in post-purchase stages.

Conclusion: Findings reveal that although many were aware of SHEIN’s unsustainable practices, persuasive strategies such as low price, convenience and incentive systems are some of the main motivators for purchases and outweighing ethical concerns. In terms of Cognitive dissonance many changed their actions due to mental discomfort. But amongst those who changed their belief instead justifications such as, comparison rationalisation, guilt compensation and temporal justification were the most recurring. The study contributed to a deeper understanding of the consumer buying decision process offering insights for policymakers and marketers aiming to promote more sustainable consumer behaviour.