Our boys share bedrooms...the two older ones are together and the two little ones are together. We've had to tweak bedtime routines for the older boys and deal with some brotherly fighting but overall it's worked out fairly well.
The younger boys have been great together. Winter3 goes to bed first followed shortly by Fall2. When they wake up in the morning they laugh and talk. Winter3 brings blankets and books and sits in bed with Fall2 playing until I get them up. When they were smaller, the boys would sometimes fall asleep together in the crib, all tangled and snuggled together.
Every so often, Fall2 wakes up very early. Like 4:30 or 5 a.m. early. He'll go back to sleep but since he's convinced that it's time to wake up he makes it his mission to wake up his brother. Through the blessing/curse of the baby monitor I get to hear the entire exchange.
It starts with Fall2 calling Winter3 in a normal, conversational voice and progresses from there.
Fall 2: "Winter3Winter3Winter3!!"
Fall2: "WINTER3 [SHRIEK! SCREAM! SHRIEK!] WINTER3!!!!!!!!!!!!!!!!!"
Winter3: [in a very sleepy voice] "whaaaaat?"
Fall2: "Yay! Yay!" [followed by much hand clapping and cheering because who wouldn't be excited to start the day?]
I can thank my lucky stars that Winter3's body tells him that it's time to go back to sleep. At this point, if he ignores his brother, Fall2 falls back asleep. Sometimes, I head over to the room, cover Fall2, pat him and try to convince him that five people in the house are indeed trying to sleep.
This morning, I opened the door to their room and didn't see Winter3 in his bed. I noticed him curled up on the heating vent behind the rocking chair with a blanket over his head. He hasn't slept out of his bed in a while now so I asked him why he was sleeping on the floor. Winter3 told me, "I tryin' to sweep. Fall2 keeps yellin' at me." Sure enough, Fall2 had gone back to sleep but only after his brother was out of view. Poor little boy! He can't run away from his brother but he can hide!!