the.com/comic relief

means A moment of humor deliberately inserted into a serious or tense work to give the audience a emotional breather before the tension resumes.

from A dramatic-criticism term that crystallized around Shakespeare's plays — think the drunken porter babbling right after Duncan's murder in Macbeth — where a comic scene is dropped into tragedy to release pressure before ratcheting it back up. The phrase itself is first recorded in literary criticism in the 1800s, with writers like Thomas De Quincey analyzing exactly this porter scene, though the technique it names is far older than the label.