Doonesbury by Garry Trudeau for February 12, 1973
Transcript:
Mark: Hello? WBBY request line! Voice: "Marvelous Mark?" I'd like to dedicate "Baby Blue" to Elmer. Mark: Oh? Whys that, dear? Voice: Well, see, I had this groovy guy who was really outasite, but then the relationship turned out to be a bummer... see, he started digging another chick. So I started going out with his best friend, to pay him back. But the whole thing got too physical, too much sex, you know what I mean, "Marvelous Mark"? Mark: Actually, "Marvelous Mark" is kinda sorry he asked... Voice: So I told him to bus off, see...