To sleep together in the same bed; also used to describe being married or living together as a couple.

(idiom) literally "to share the same bed but have different dreams"; used to describe partners who live or work together but have separate goals or secret intentions; strange bedfellows; marital dissension

to sleep in the same bed but dream different dreams; describes people who work together or live together but have different intentions or goals; also used to describe an unhappy marriage.