A deleted affair, in literary terms, is a romantic relationship that is revealed to have occurred at some point in the past, but is never referred to in the present story. Specifically, it occurs when such a relationship surfaces after the main story seems to have established that no such prior relationship occurred. Usually such affairs are revealed in later installments that follow the original work. This form of retcon

Retcon

Retroactive continuity is the alteration of previously established facts in a fictional work. Retcons are done for many reasons, including the accommodation of sequels or further derivative works in a series, wherein newer authors or creators want to revise the in-story history to allow a course...

is often poorly received by readers of the story, as it is seen as a betrayal of the original tale.