Any plans tonight? Oh, nothing really. Just going to

Reminds me of the private detective that was hired by a wife that was suspicious her husband was fooling around on her. Turns out the wife that hired him was right. Her husband was indeed fooling around.

He was banging the detectives wife.

wasnt this premise a writing prompt on a subreddit?
edit: it was. https://www.reddit.com/r/WritingPrompts/comments/6i00oy/wp_you_hire_a_female_prostitute_tell_her_to_meet/