The fourth season of the British drama series Last Tango in Halifax, currently airing on PBS, continues the story of Alan Buttershaw (Sir Derek Jacobi) and Celia Dawson (Anne Reid), who rekindled their love for each other 60 years after they first met and who are now in their seventh year of marriage. While they’re settling into a new home together, their clashes over life’s little dramas create tension that they must work through alongside their extended family and friends. During this 1-on-1 phone interview with Collider, Jacobi talked about why he was so happy to …