The McKees live in the same apartment building in New York City that Tom Buchanan uses to conduct his affair with Myrtle Wilson. Both McKees attend the party at the apartment, and Mr. McKee attempts to impress people with his skills as a photographer.
Catherine is Myrtle Wilson's sister. Mr and Mrs McKee are Myrtle's friends from New York.
Mr. McKee invites Nick to lunch someday. That is the extent of their conversation. Mr. McKee and his wife are friends of Myrtle Wilson's who show up at the apartment Tom Buchanan keeps for her in the city.
Mr and Mrs
No -_-
Tom wants Mr. McKee to photograph Myrtle Wilson, his mistress, whom he takes to New York for a rendezvous.
Mr and Mrs is correct or Mrs and Mr is correct
Mr. and Mrs. (ex. "Hello, Mr. and Mrs. Evans" instead of "Hello, Mrs. and Mr. Evans")
Mr. & Mrs. Smith
In the US it is normally Mr. and Mrs.
that Gatsby's king of Germany family.
Dr. and Mrs. or Mr. and Dr.
The photographer at the apartment party in The Great Gatsby was Mr. McKee. He takes a group photo of the guests at the party, including Jay Gatsby and Nick Carraway.