To sleep at all.
From Shakespeare's "Cymbeline" Act III Scene IV.
sleep together
To have sex with each other.
sleep in
To sleep late; to go on sleeping past one's customary or planned hour.
sleep with the fishes
To be dead, with one's corpse disposed of in a body of water.
sleep on
To postpone (a decision) at least overnight, to avoid making a hasty c…
sleep with
To have sexual intercourse with.
sleep off
To get rid of (a pain, illness, condition) by sleeping.