Few studies have investigated learners’ emotional experiences and the interactions between emotion, cognition, and activity in the flipped foreign language classroom (i.e., a mixed teaching mode that combines in-class teaching and off-class self-directed learning). This study, from the perspective of perezhivanie (a concept from sociocultural theory), addressed these research gaps by exercising a longitudinal narrative study on a total of 32 Chinese-as-the-first-language university students of English who attended a 15-week English course with this teaching design. Among them, eight focal students were randomly selected for further evidence of the characteristics of the interactions between emotion, cognition, and activity. The results showed that the participants experienced more of positive emotions than negative emotions in the flipped classroom (FC) context, which supports the efficacy of the pedagogy. But most importantly, complex interactions between emotion, cognition, and activity were revealed. Generally, (negative) positive emotion, cognition, and activity were interconnected; however, what is also evident is that learners’ emotions either promoted or inhibited their cognitive functions, and positive and negative emotions did not necessarily correspond to positive and negative activities, respectively. This is due to the presence of dynamic, developmental, and historical sociocultural mediators in learners perezhivanija, be it teacher, peers, technology, teaching materials, teaching activities in an FC, or the learners’ previous English learning anecdotes, etc.