Dr. Demento had a few not-so-subtle classics:

You let me play with your yo-yo, I'll let you play with mine,
You let me play with your yo-yo, I'll let you play with mine.
You got a wiener, I got a bun,
We can put the two together, boy, and have some fun,
You let me play with your yo-yo, I'll let you play with mine.

--this is to the same tune as "Alice's Restaurant"

I don't remember the verses at all, but there was also "My Girl's Pussy," purportedly about a cat, but obviously not.

--seed