Another role of the wedding guest in Samuel Taylor Coleridge's "The Rime of the Ancient Mariner" is to function as a stand-in for the reader. The wedding guest provides a reason for us to hear the tale, and because the ancient mariner simply walks up and begins telling the tale, the reader gets the feeling of being taken aback and caught off guard, just as the wedding guest is. Also, the wedding guest is useful in conveying one of Coleridge's themes that knowledge leads to sadness, as for all intents and purposes, the wedding guest should be joyous, celebrating a union and a new beginning for a happy couple.

However, after hearing the mariner's tale, the wedding guest is forever changed, and their world is forever slightly diminished by the knowledge of what the mariner has experienced. Further, sea-voyages have often been used as metaphors for weddings, as the couple is embarking on a trip into the unknown together. While this metaphor alludes to the idea of endless possibility, because of the guest's presence and the mariner's tale, the reader's mind turns toward some of the more negative outcomes of such a journey.