Given the following context:

Twenty-three year old Joanna Drayton's unannounced early return from her Hawaiian vacation causes a stir when she brings her new fiancé to her upper-class family home in San Francisco. He is John Prentice: a 37-year-old black  (the 1967 dialogue uses the term Negro throughout) physician and medical professor, whom she met just 10 days prior, whose first wife and young son were killed in a train accident eight years earlier.
Joanna's parents – newspaper publisher Matt Drayton and his wife, art gallery owner Christina – are avowed liberals who have always instilled in her the idea of racial equality. Although they try to hide it, Joanna's parents and in particular her father are initially upset that she is planning to marry a Negro man. The Draytons' black maid for 22 years, Tillie, is even more horrified, telling Joanna that John is trying to "get above himself" by marrying a white woman, but Joanna
asks why it is okay that she loves Tillie but she shouldn't love John, who is "just as black".
The Draytons are unsettled by her engagement with John, since they never thought that her choice would be a Negro man, and further unsettled by John's decision that if Joanna's parents do not accept the engagement that day, then he will end it.
Adding to the situation is that Joanna, at first intending to join John in a few weeks in Geneva for their planned marriage ceremony, has now decided that she will join him when he leaves after dinner to fly to a meeting in New York City, then onward to Switzerland, where he is an assistant director with the World Health Organization. She has also invited John's parents to fly up from Los Angeles for dinner, so they can all become acquainted. Due to this invitation, what was intended to be a sit-down steak dinner for two turns into a meet-the-in-laws dinner party. Furthermore, John is forced to reveal that he had not yet told his parents of his intention to marry a white woman.

answer the following question:

What are the first names of the two people who join Joanna, John, and John's parents for steak? 

Matt