The episode: “Santa Claus Conquers the Martians,” ep. 321
The riff: Spoken by Tom Servo as a martian father warmly greets his two young children with gentle headbutts (as is martian custom).
The explanation: Servo is referencing Peter Sellers’ famous telephone conversation from the war room of Stanley Kubrick’s “Dr. Strangelove.” In the scene, Sellers’ character (the American president) is trying to break the news of possible impending nuclear war as tactfully as he can to the Russians, but he is clearly reticent. Here, I think they use the line because given the poor acting, the sentiments of the martians are just as phony as the American president’s pleasure that the line is “coming through just fine.”
Novelty factor: I was always amused by this line, but I have to admit I didn’t catch the reference. I should probably rewatch “Dr. Strangelove” in the near future. In the video below, the inspiration for the riff stars around 22 seconds in.