Over the years I tried so many different bed options for visiting g.children. In my house, the third - small bedroom was also my study/office. For a few years I had bunk beds in there, also had blow up bed to use.
The second bedroom in my flat is a strange shape and cannot take a full sized double bed. For a while I did have a sofa bed, 3 ft wide which pulled out to a full sized double bed. Had to have the radiator moved to give people about six inches to get past it. Have now turned that into my craft room, got rid of that sofa bed and got a got quality z bed. Full single size when open 3 ft x 6.3. Folder and cover on it is out of the way. Friends who have used it in overnight stays with me say it is comfortable.
Do remember that boys start to grown during their teen years. My youngest grandson, now 15 years of age is well over six foot tall. He lives nearby, so I have no problems there, but no way could two of him share a sofa bed!!!!