Our beds this time around are separate. Though the thought crossed our minds...briefly. Living with three dogs jumping all over the bed helped with the decision.
My first bus had a combination bed & flop space for all to enjoy. No futon just a bed that everyone could just hang in (that was back in the 70's so not odd at the time)
Worked out fine, just had to take a broom to get the days living out of the bed, pull down the blankets and hit the sack.
In my 60's now and we wanted to have a room to go to when we are sick or just want to be alone.
That and a story my daughter shared about her bed being the flop spot in her first apartment she shared with a roommate and after working a 12 hr day came home exhausted to a bed that roomies friend had gotten drunk, spilled his beer on and then proceeded to piss his pants all over.
She moved out the next day when roomie wouldn't swap beds for the night.