But if you'll recall, there's someone else who vowed to stay by William's side, who was nowhere to be seen last night. Jessie (Denis O'Hare) found William, his ex, after William left without saying goodbye. The reveal, which came in the winter finale , added another layer to William's character. He left Jessie because he didn't want to burden him with his cancer diagnosis, but Jessie said he wanted to live out William's remaining days with him. William brought him to the Pearson family's holiday gathering, suggesting Jessie was in it for the long haul.