In Chapter 7 of The Great Gatsby, what ironic situation is occurring on the drive to town?

On the drive into New York, Tom discovers that Myrtle is going to be moving away with her husband.  Ironically, Tom seems to be losing both his wife and his mistress in the same afternoon.  Also, the same thing is happening to both Tom and Wilson.  They both have discovered that their wives are leading secret lives.

While this turn of events is happening, a series of ironic misunderstandings are also happening.  Myrtle sees Jordan and assumes that she is Daisy.  George sees Gatsby's car and assumes that it is Tom's.