Cora and Robert
Some might rank these two higher, but they hit rock bottom more than a few times, most notably due to Robert’s infidelity with the maid, Jane. They struggle with indecision again when Cora flirts with Simon Bricker, but she stops his advances quickly. The worst part is when their daughter, Sybil, dies; Cora wants to take her to the hospital, but Robert disagrees and is the reason for her death.
Mary and Henry
Lady Mary has no shortage of enamored suitors, but it doesn’t go both ways. Henry Talbot is the first man she loves after her husband Matthew’s death, and even though Mary doesn’t like race car driving due to her husband dying in a crash, she accepts Henry’s hobby. The pair weds at the end of Season 6, but their love story still couldn’t stand up to Mary and Matthew.
Edith and Bertie
When Edith met Bertie Pelham, there were no red flags, unlike some of the other relationships on this list. He supports her work and helps her get her magazine published; her passions matter to him! Despite Bertie proposing, they do have one bout of jealousy when Mary reveals Marigold is Edith’s child, but Bertie forgives her, and they still get married.
Rose and Atticus
Entering the show in Season 3, Lady Rose MacClare and Atticus Aldridge fall in love, marking a passionate interfaith relationship (one of the few moments of diversity in the show) with Romeo and Juliet undertones. Their parents insult each other, and an enemy even tries to make it look like Atticus is heating up to Rose. But the two persevere and eventually marry.