This case study explored the short-term international co-teaching experience of pre-service general education teachers who were paired up with intern special education teachers (N = 8) to provide English language instruction to students in South Korea. Pre-, during-, and post-data were collected to investigate how the participants experienced their co-teaching. The narratives of two participants were chosen for phenomenological analysis, reflecting an overwhelmingly positive and a rather negative co-teaching experience. The key ingredients to a successful partnership were identified as open communication, the willingness to accept both positive and negative feedback, the willingness to learn from or get inspired by someone who may have less teaching experience, mutual respect and trust, compatibility of personal characteristics, and frequent check-ins. The potential threats to a positive relationship were identified as mismatched personalities, incompatible teaching goals, the lack of co-planning, conflicting approaches to lesson planning, unequal roles, infrequent check-ins, and lack of trust and respect. Despite these challenges, the findings indicate that immersing teacher candidates in co-teaching experiences resulted in positive perceptions of co-teaching and increased the participants' skills related to collaborative teaching for all but one candidate. The findings have led to recommendations for the successful set-up of co-teaching experiences.