This paper explores the interplay of Taiwanese adolescent English learners' motivational selves and their parents' expectations, with a special focus the identified perceptions of both teenage leaners and their parents towards English learning as a duty and obligation. Using the L2 Motivational Self System (L2MSS, Dörnyei, 2009), the qualitative study foregrounds the cultural and relational aspects of the self system in understanding language learning motivation. Results from semi-structured interviews suggest that parental expectations of children's English learning exhibit a duality characterized by the hope that their children will become successful members of the globalized world and a belief that English learning is a basic responsibility for their children. Adolescent language learners' and their parents' actual selves, including their identification with societal roles and social obligations, mediate between parents' investments in their children's English education and teenage learners' perceived obligations to meet parental expectations. The paper concludes by suggesting further research on parental expectations and the development of global selves, and on the synergized effect of language learners' actual selves and future self-guides in motivating language learning.