The shift of focus from a cognitive to social view has drawn the attention of second language assessment researchers to delve into interactional competence as an intriguing topic in paired oral tests. To fill the gap on how interactional patterns compare across L1 and L2 interactions this study was specifically set to explore and compare 45 paired interactions of L1 English speakers, L1 Persian speakers, and L2 English learners. While the findings indicated that the collaborative pattern was the most common pattern in the three groups less than half of the interactions in total were collaborative. Furthermore, not all the interactional patterns were found in all the groups. The frequency and prominence of the common patterns also varied. The findings could be explained by cultural norms of speech (e.g., in taking turns) and interlocutor effects (e.g., dominating the conversation or adopting a passive role). The findings imply challenges for fair assessment when using paired tasks as assessment tools. Furthermore, the findings call for rubric development and rater training programs to include description and discussion of interactional patterns to help raters improve their understanding and rating of paired interactions.