Oh, my! Censor the old playground songs. I think I first learned this one in first grade, or a very close version.
One version was Ta-ra..., Mary show us your butt today. Another verse about buggery.
Like curmudgeon, my sex education began with my earliest school days. A comic pamphlet of Popeye, Olive Oyl, Bluto and Hamburger? (Can't remember the name) doing it all in every possible position which I obtained in trade for a banana and candy was confiscated when my mother found it, but I remember my father laughing about it for a long time afterwards. I wish I had got it back. Kids are so pure and correct today.