The sharing economy has recently gained momentum among managers, public policy makers and academics as a great opportunity to boost sustainable consumption through sharing or selling durables or semi-durables. The present paper contributes to this debate by investigating the propensity of consumers to give in to temptation on second-hand peer-to-peer (P2P) platforms, which provide a favorable context for self-licensing behaviors. A survey was conducted in 2015 amongst 541 active buyers on the French P2P platform leboncoin (equivalent of US craigslist) addressing questions relative to their buying activities in the previous year. The results show that materialistic and environmentally conscious consumers are more likely (than consumers who are not materialistic and environmentally conscious) to be tempted in the context of second-hand P2P platforms as these offer justifications that help reduce consumption-related cognitive dissonance. This finding corroborates the counterproductive role of collaborative consumption for sustainability in certain conditions. Theoretically, the research contributes to further developing the emerging self-licensing theory in the context of second-hand P2P platforms and understanding impulse buying on this new web interface.