Another article that is referenced at the end of @memills article talks about this.
Most research does show that making more money is associated with having more affairs. In a 2001 study using a nationally-representative sample of the USA, David Atkins and his colleagues found people making more than $75,000 were 1½ times more likely to have an affair compared to those making less than $30,000. In that same study, people with graduate degrees were 1¾ times more likely to cheat on their spouses than those who did not graduate high school. A lot of other evidence points to high status people having extra-marital sex, but interpreting this can be tricky. Does achieving high status cause us to desire an affair, or do the same personality traits that cause us to achieve high status also cause us to be more likely to have affairs? It’s probably a little bit of both.
This article references this study but I can’t past the paywall.