"I Do, Adieu" is the fifth-season finale of the American television sitcom Cheers, written by Glen and Les Charles and directed by James Burrows. It aired on May 7, 1987, on NBC. During the fifth season, Sam Malone repeatedly proposes to Diane Chambers, and she refuses repeatedly until she accepts engagement in "Chambers vs. Malone" (1987). In the previous episode, "A House Is Not a Home", Sam and Diane bought a house together. Before this episode aired, Ted Danson decided to renew his contract with the show as Sam Malone, while Shelley Long decided to quit the series, which could conclude the on-and-off romance of "Sam and Diane" that went on for the first five years since 1982.
