Simon's mother died during childbirth after finally delivering a male heir. His father, Lord Hastings, was only concerned with the boy's ability to carry on the family name and showed no grief for his wife.

in any room I entered. Come. You can speak. I understood you well enough. And I will help you to overcome this stammer of yours. . Scraps from the loft Bridgerton S01E02 Recap - TV Tropes

Anthony Bridgerton is furious about the arrangement, distrusting Simon’s rakish reputation and fearing for his sister's honor. The Origin Story: Simon’s Past

When young Simon developed a stutter, his father rejected him as a "failure" and sent him away to be hidden from society.

A close friend of his mother, Lady Danbury, intervened, helping Simon find his voice and gain the confidence to eventually confront his father.

The episode follows the fallout of the Vauxhall Gardens celebration , where Daphne Bridgerton and Simon Basset, the Duke of Hastings, agreed to a fake courtship.