Normalcore

A word describing a stage of being in which a person is feeling intense emotions, such as anger, obsession, mania, grief, or joy, while pretending they are calm and collected, despite being very obviously not. The term is primarily used in an ironic or joking manner.

"His dog is actually super cute! I'm going going to steal that thing, so help me god. I'm so normalcore about it, don't worry, hahaha!"