The first time two girls sleep together let them tie two of their big toes together with woollen yarn, and the one with the shortest piece of broken string left attached in the morning will be married first.
Northern Ohio.

The first time two girls sleep together let them tie two of their big toes together with woollen yarn, and the one with the shortest piece of broken string left attached in the morning will be married first.
Source: Current Superstitions (1896), entry 176.
Fanny D. Bergen, editor.
Modern normalized navigation; the historical attribution above remains unchanged.