The relationships between Marie Tovesky Shabata and Emil Bergson in "O Pioneers!," and between Daisy Buchanan and Jay Gatsby in "The Great Gatsby," are similar in the sense that the situations that these characters are in are very similar. Marie and Daisy are both married and both their husbands are becoming distanced from them. They both seek a change due to their dysfunctional relationships and therefore their motive for committing adultery is similar. On the other hand one could argue that the relationships are actually very different in the sense that one has more history than the other. For instance Gatsby and Daisy had met along time ago during the war where they declared their love for each other; In contrast, Emil and Marie's relationship is new and flirtatious.
It is therefore clear that there are significant differences in the two relationships. A mentioned earlier in The Great Gatsby, Gatsby's relationship with Daisy has more history. Daisy fell in love with lieutenant Jay Gatsby, who was stationed at a base near her home. When Gatsby left for war, Daisy reluctantly married Tom Buchanan. Before the wedding she repeatedly cried, "Tell 'em Daisy's change' her mine" (76) while opening a letter from Gatsby. This shows that there was history between Daisy and Gatsby, even before the marriage between her and Tom. On the other hand in O Pioneers!, Marie and Emil did not really have much history. They did play with each other as children, however they did not declare their love for each other like Gatsby and Daisy did. Therefore one could argue that Emil's relationship with Marie is fresher and does not stem from their past encounters. The relationship in The Great Gatsby is a continuation of the past; While in O Pioneers!, the relationship is new.
However one could argue that Marie and Daisy are having new relationships for the same reasons. This is due to the fact that both marriages seem are dysfunctional.
