Why, in the US, are attractive women called foxes?

Which is funny, because if you have ever actually been to an Eastern European country, American breasts are not all that impressive.

I wonder if “foxy” was popularized by the media because it’s close to “sexy,” and there may have been a time when “sexy” wasn’t allowed (you certainly don’t hear it in reruns from shows before about 1979), but you could get away with “foxy.” That may be how it made its way from black vernacular to the general population. It certainly was used on TV a lot in the 1970s, although I can’t remember when it became OK to say “sexy.” There was probably a time when it was OK to say it about a one-off character, but you didn’t want to say it about your main character (or anything she was doing or wearing). Anyone have a better memory than I do?