Polarization and group formation processes on social media networks have received ample academic attention, but few studies have looked into the discursive interactions on social media through which intergroup conflicts develop. In this comparative case study, we analyzed two social media conflicts between farmers and animal right advocates to understand how conflicts establish, escalate, and return dormant through issue and identity framing and the discursive use of emotions. The results show that the two groups used the same set of frames throughout the three phases. We identify this as a symmetric conflict framing repertoire. The groups both use a dominant moral frame (animal welfare is of absolute value), but express distinct views on policy solutions. This triggers a contestation of credibility (who knows best and who cares most for animals) in which the two groups use the same set of issue and identity frames to directly oppose each other. The binary opposition is initially established through issue framing but escalates into an identity conflict that involves group labeling and blaming. The discursive use of emotion reinforces this escalation in two ways. First, it reinforces a vicious cycle in the contestation of credibility: While emotions are implicitly used to frame oneself as caring and trustworthy, emotion is explicitly used to frame the other party as deceptive and irrational. Second, disputants use collective emotions as a response to the other group’s offensive actions (blaming) and as a justification of one’s own collective actions. We discuss how this conflict differs from previously studied conflicts to provide plausible explanations for these findings.