Although research on humorous practices of Anglo-Australians has received much attention, the understanding of those practices by members of various multilingual communities in Australia has not been much studied. In this paper, we look at metapragmatic comments on concept familiarity in relation to conversational humour, particularly focusing on Mandarin Chinese speakers’ perceptions of conversational humour in Australian English. In order to explore what role ‘familiarity’ plays in (inter-)cultural conceptualisation of humour, we analyse interview data where speakers of Mandarin Chinese provide their metapragmatic comments on humorous exchanges among Australians. Drawing on approximately 8.2 hours of interview data elicited by a segment from the reality television gameshow Big Brother 2012, i.e., a teasing sequence between two acquainted persons, it is suggested that the concept of familiarity is the one most frequently alluded to in the theme of how participants ‘draw the boundary’ between intimates and acquaintances. From the analysis it emerged that Mandarin Chinese speakers’ evaluations of humorous exchanges in Australian English are driven by their culturally-informed perceptions that are conceptualised through various emic notions, e.g. guanxi (‘interpersonal relationship’), various labels for classifying different relational distance, and qiji (‘opportune moment’). The findings of this exploratory paper suggest that the role of ‘familiarity’ in relation to humour is crucial in the perception of appropriateness of humorous practices in interaction, especially across cultures.