We sleep 3 to a bed most nights. It's a bit complicated sometimes, especially when it comes to blankets. I tend to sleep in the middle, because I'm the one who gets coldest. My husband can NOT sleep in the middle because he sweats way too much.
It is nice, but it also helps to have a second room where someone can sleep alone if they choose to. We will be moving to a new house together at the end of the year and we plan to have 2 bedrooms for adults, so our sleep options are more open.