I don’t know how many of you have slept ‘top to tail’ during your childhoods? For those who haven’t, it’s an arrangement where two people share a bed with their heads at either end of it, with the bedclothes ‘open’ at both top and bottom.
It was widely used (and may still be, for all I know) for children of similar ages but different sexes when sleeping accommodation was tight. The idea being that it was less likely to lead to physical intimacy, and therefore sexual curiosity or indeed activity.