For the second time...A-HEM!
Jo, c'mere a minute--I have something for you...

I'm not sure it's being manufactured any more, but yes, shag carpeting was very popular in the '70's. I don't think that interpretation of shag was known very much here till that "The Spy Who..." movie came out. I do know lots of people hadn't known it--the term was "explained" in the media. (By innuendo, of course.)