Since u asked this vraag 8 months ago...so much has been revealed including the bombshell that the First Lady, Mellie Grant, has known about the affair for quite some time and encouraged it for the purpose of making Fitz the best president he can be. She has already confronted both Olivia and Fitz about it and so far the earliest confrontation was the flashback scene between Mellie & Olivia in the White House hallway discussing the pin/Fitz taking Olivia to see the original Constitution of the United States instead of inviting the First Lady,his wife.