Question

The affair is quite above board, I assure you my love. What is the pun in john's statement?

Answer 1

The affair is quite above board, I assure you, my love.

The pun in John's above statement is that he is not having an affair with any lady but with a ghost.

(Pun is a joke which gets arise when the meanings of the words differ but they sound similar. In this sentence, the word 'affair' means an encounter with the ghost and not with a real woman.)