Siblings sharing a bed?

Both are boys and are 14 and 12. I know they are too old to be sharing a bed but there isn't much I can do. My father lives in the second room upstairs (across from the boys) and we the parents share our room with our other 3 children, 1 which we share the bed with and the other 2 in a bunk bed. Does anyone have suggestions for what should or can be done?