Bobby Darin and Jimmy Durante on What's My Line in 1965

Bobby Darin and Jimmy Durante were good friends by the time this aired, and you can see that in the way Bobby reacts when Jimmy is revealed to be the "What's My Line" mystery guest. It's also interesting to note that Bobby is the last one on the panel to take his seat during the ovation they give Jimmy toward the end. His respect for the great Jimmy Durante was absolute, and he was clearly so thrilled just to be in his presence.