In Chapter 7 of The Great Gatsby, why is Myrtle Wilson upset when she sees Tom and Jordan?
In her wondering of what to do with themselves on a torrid afternoon, the jaded Daisy suggests that she and Tom, Nick and Jordan and Gatsby all go to the city. Noticing the electricity betweeen Gatsby and his wife, Tom's temper cracks and he trembles as he tries to control himself. Then, when Gatsby suggests that they all go in his car, Tom asks if it is standard shift. When Gatsby replies that it is, Tom says he will drive it and Gatsby can take his coupe; this is distasteful to Gatsby, but Tom overrides his objection that there is little gas in the car by replying that he can stop at a drug store, adding sarcastically, "You can buy anything at a drug store nowadays," implying the small value that he puts on his mistress, Mrytle Wilson.
Daisy refuses to accompany Tom in Gatsby's "circus wagon"; instead, Jordan and Nick get in. As they pass through the Valley of Ashes, Jordan suggests that Tom buy gasoline, so, angrily, he screeches into the lot of Wilson's Garage. While they are there, Nick feels some eyes watching "with peculiar intensity from less than twenty feet away." These eyes belong to Myrtle Wilson, who mistakes Jordan for Daisy:
...her eyes, wide with jealous terror, were fixed not on Tom but on Jordan Baker, whom she took to be his wife.
Previously, Myrte has expressed her jealousy for Daisy in the New York apartment when she repeatedly said Daisy's name over and over until Tom punched her in the nose.