This study investigates how co-branding collaborations between luxury and fast fashion brands affect consumers' perceptions of brand identity and brand attitude. The study compares how two generations, Generation X and Z, perceive this type of collaboration. Through a qualitative approach, focus group interviews have been conducted and then analyzed. The final result shows that Generation X values exclusivity and authenticity to a greater extent, which leads to skepticism about such collaborations. In contrast, Generation Z tends to be more open-minded and has a greater ability to adapt, where authenticity and visual affinity weigh more heavily than the classic values linked to brands. The study is based on theoretical frameworks such as Generational Theory, Customer-Based Brand Equity (CBBE), Brand Extension Theory and Brand Relationship Theory. The aim is to shed light on the cognitive and emotional reactions that have shaped consumers' attitudes. This work contributes insights into how co-branding strategies should be considered to effectively reach different target groups based on their generation-specific values and expectations