Manhire’s “How to Take Your Clothes Off at a Picnic” (1977), Sheet Music: Poems 1967-1982 (1996) is a humorous riff on picnic adultery:
It is hardly sensuous, but having
Eaten all the cold meat and tomatoes
You forget to remove your trousers
And instead skip stones across the river
With some other man’s wife . . .
See Billy Manhire. “How to Take Your Clothes Off at a Picnic.” In How to Take Your Clothes Off at a Picnic. Wellington, NZ: Wai-te-ata Press, 1977.