In The Great Gatsby by Fitzgerald, why do Tom and Daisy stay together? What were they each seeking in their marriage?

Tom and Daisy stay together most likely out of convenience. Both characters come from families of wealth, and this affords them a very leisurely lifestyle. By Nick Carraway's account, both are very "careless" people, both in the way that they spend their time and in the way that they treat other people. This carelessness is what leads them both into affairs. Tom has an affair with Myrtle Wilson and Daisy has an affair with Jay Gatsby. However, if either one of these characters were to commit fully to these respective affairs, that is, if they were to leave their spouse, their carefree lifestyles would be unalterably changed due to the social ramifications of such an act. Both Tom and Daisy are very careful to hide their affairs from public view because at the time during which the story is set, infidelity would be nothing short of scandalous. It seems, then, that what they were seeking in marriage is the social status that comes along with marrying a person of the same social caliber. This can be seen when Tom first realizes that Daisy is having an affair with Gatsby, for Tom immediately denounces Gatsby's illegal business practices, thus singling him out as someone who does not truly come from "clean" wealth. Therefore, Gatsby does not have the same social pedigree that affords Tom and Daisy their carefree lifestyle, and Daisy's eventual decision to choose Tom over Gatsby could be indicative of her desire to maintain the carefree lifestyle that their marriage affords.