Social interaction is inherently bidirectional, but research on autistic peer interactions often frames communication as unidirectional and in isolation from the peer context. This study investigated natural peer interactions among six autistic and six non-autistic adolescents in an inclusive school club over 5 months (14 45-min sessions in total) to examine the students' peer preferences in real-world social interactions and how the preferences changed over time. We further examined whether social behavior characteristics differ between student and peer neurotype combinations. Findings showed that autistic students were more likely to interact with autistic peers then non-autistic peers. In both autistic and non-autistic students, the likelihood of interacting with a same-neurotype peer increased over time. Autistic and non-autistic students' within-neurotype social interactions were more likely to reflect relational than functional purposes, be characterized as sharing thoughts and experiences rather than requesting help or objects, and be highly reciprocal, as compared with cross-neurotype interactions. These peer preferences and patterns of social interactions were not found among student-peer dyads with the same genders. These findings suggest that peer interaction is determined by more than just a student's autism diagnosis, but by a combination of student and peer neurotypes.