One social issue highlighted in Ch. 7 is infidelity among spouses. We see Daisy boldly kiss Jay in front of Nick and Jordan. We see a sick George Wilson tell Tom he finally realized something has been going on with his wife and the implication is, of course, that she has been having an affair. Another social issue mentioned in the chapter is interracial marriage which is another reference, like the one in Ch. 1, of Tom's bigotry and racial intolerance. There is also the social issue of cars. The chapter opens with Nick personifying cars when he says that the cars would turn into Gatsby's drive with hope and expectation only to turn away sulkily in disappointment at the realization there is no party. Daisy and Jay drive to New York in Tom's car while he, Nick, and Jordan take Gatsby's car. Tom lets George think he can sell George Jay's car and that leads George to think later that Tom owns that car. It is Jay's car that Daisy drives and kills Myrtle Wilson with.
The growing tension among the characters, particularly Tom and Jay, is represented by the intense heat. Daisy complains about it being so hot and Tom chastises her for complaining whereupon Jay tells Tom to leave her alone. This begins the blow up between Jay and Tom.