27. Franklin D. Roosevelt and Lucy Mercer
Considered one of the more honorable presidents, FDR helped the nation get through Pearl Harbor and WW2. However, during his presidency he had an affair with his secretary Lucy Mercer. Elenor, his wife, eventually found out about the affair after discovering a love letter he wrote to Lucy. Elenor was furious and wanted a divorce. However, they stayed together for the sake of his political career.
