To the tune of "She'll be comin' round the mountain when she comes"
(which turns into a double entendre in this case)
I heard it years ago on a recording by Joe Mondo, who may well have been a very local Connceticut singer.

They'll be footprints in the dashboard upside down
They'll be footprints in the dashboard upside down
Won't your parents be disgusted/ when they see your cherry's busted
They'll be footprints in the dashboard upside down

They'll be footprints in the dashboard upside down
They'll be footprints in the dashboard upside down
O won't your folks be surprised when/ they see your belly risin'
They'll be footprints in the dashboard upside down

Upside down, Upsde down
They'll be footprints in the dashboard upside down
O your folks'll be flabbergasted/ when they meet the little bastard
They'll be footprints in the dashboard upside down

--Charlie Baum (a little bit red-faced that his brain retains stuff like this)