The University of Florence's Language Center (CLA) and the Florence seat of an American university renowned for its language programs, Middlebury College, twice intertwined their English and Italian B2/C1 foreign language courses to produce an English/Italian reciprocal learning space. In addition to disparate organizational constructs, the two institutions had slightly differing goals. Both institutions sought multiple, peer-speaking opportunities; however, in addition, Middlebury aimed for intercultural exchange with local peers. To achieve these multiple objectives, our joint courses included elements of group work, collaborative learning, and the latter's language-acquisition offspring, task-based learning. Research drawn from the fields of management, psychology, pedagogy, sociology, and translation studies, in addition to second language acquisition, guided our instructional design choices. Students worked together outside the classroom, co-constructing knowledge in increasingly complex tasks, to produce tangible outcomes. These joint activities provided students with a space to confront their interpretations and expectations of the L2 culture with an insider's view. Students experimented with simultaneous, sequential and reciprocal bilingualism. In the second edition of the course, Spanish L1 speakers were present in both universities, co-constructing their knowledge multilingually. The article describes the courses' format, activities and hurdles, for those interested in setting up bilingual lessons, as well as citing germane studies from a variety of academic disciplines which guided course design.