This paper explores conversational humor between friends and demonstrates through a systemic functional linguistic (SFL) perspective how friends play with evaluative meanings in their humor to achieve bonding and affiliation. Sequences of talk that feature shared laughter are analyzed and it is shown that speakers make humorous contrasts between social values related to their friendship groups and community memberships. Using SFL tools like appraisal, the examples reveal contrasts as well as layering of evaluations of experiences, people, and things in the speakers' lives with underlying community values known to be shared with those with whom they are joking. It is argued that this “convivial conversational humor” is one kind of affiliation process in which friends manage their connections to each other and to the social world. This paper contributes to SFL theory by providing new insights into humor and conversational talk, and also builds on the theory by offering connections between humorous uses of appraisal and affiliation as a model for social bonding. By doing so, this paper aims to highlight the value of a systemic functional linguistic perspective on conversational humor.