Final answer:
The question involves literary analysis of trust and honesty in relationships, referencing an affair that occurred in the past. John's statement implies his resignation to Elizabeth's continuous mistrust.
Step-by-step explanation:
The questions posed are related to the themes of trust, honesty, and the ramifications of past actions in relationships, which are prevalent in literary studies, particularly within the context of a drama or novel. The affair that the question refers to seems to have happened some time ago, as there's a sense of a lingering effect rather than a recent event. When John tells Elizabeth, "I'll plead my honesty no more," it implies a deep frustration and resignation. He no longer wants to defend his truthfulness and integrity in the face of continued suspicion or mistrust; his statement indicates a pivotal moment in their relationship where he decides to stop attempting to prove his honesty.