If Germany had to be honest with himself, he didn't really mind it when Italy slept in his bed.
He just did't know how to deal with it. Actually, he didn't know how to deal with most displays of affection from the Italian. Italy was an affectionate being by nature and it was only natural that he would want to express his affection to his friends in any way possible. Hugs were a daily thing, as was holding hands and hooking arms. Japan usually tolerated the invasion of his personal space up to a certain point, but Germany just couldn't seem to deal with his cuddly friend. After all, Germany wasn't known for being the friendliest country in the world. If there was a list of the top ten friendliest countries Germany would bet money that he would not be on it. Italy on the other hand, would be at the top.
Well, maybe he would be behind Lithuania. The quiet nation could stand to hang out with Russia and Poland and still be nice to both of them. Finland was also extremely nice(although the Christmas-loving country could be absolutely terrifying sometimes when he wanted to be). And then there was that one guy who's name he couldn't remember but who was always polite and really quiet and it was driving Germany insane that he couldn't remember his freaking name!
Anyway, the point was that Italy was extremely friendly, nice, affectionate and cute and Germany was not any of those things, nor did he know how to deal with a person who was any of those things. So usually Italy's attempts at smothering his blonde friend with affection were met with embarrassed yells and violent shoves(Not too violent of course, he didn't want to hurt his friend). Sometimes Germany wished that he didn't get so embarrassed, but he just couldn't help it. When he was growing up, physical displays of affection weren't common. Prussia wasn't really the type to hug or cuddle anyone, even his precious little brother. But there were some moments where Germany could express his affection for his friend and he wouldn't be too embarrassed.
Italy had nightmares sometimes. They didn't happen every night but they happened enough, and usually Italy would come running to the strong arms of his German friend sobbing out the details of his scary dream. The most common ones were usually about a monster eating his pasta or going to a world meeting naked, and Germany would sigh and reassure him that no monster was going to eat his pasta and yes, he would make sure that Italy was fully clothed before going to a meeting.
But sometimes his nightmares were different. Sometimed his dreams were filled with a lonely little boy in a maid's outfit just sitting in a beautiful flower field and patiently waiting for a another boy to come home. A boy with eyes that were so blue they could rival the ocean and a small smile that was as bright as the sun with a laugh that could brighten up the darkest of days. And the boy in the maid's outfit would sit there, picking flowers and waiting for his friend.
But as days and nights went by, and as seasons passed, that boy never came back, leaving the other still waiting. Constantly waiting and hoping while always keeping a smile on his face because the other boy had always liked his smile. So every day, even as his hope dwindled and his eyes filled with tears, his smile grew bigger and bigger until he was positively beaming at every moment of every day. Because surely if he kept smiling, that boy would come back to him. But still, that little boy with his blue eyes and his bright smile and his amazing laugh never came back.
Maybe those dreams couldn't be counted as nightmares because they weren't scary and they didn't have any monsters, but whenever Italy woke up from them his chest felt as though his heart had been ripped right out, and his cheeks were soaked with his salty tears. After Italy had those dreams he would pad to Germany's room and slowly open the door. On those nights there was no running and jumping into bed, just quiet tears and a slim figure slowly crawling under the covers next to his muscular friend. He would burrow into Germany's side, and soon the back of the German's shirt would be soaked in warm tears.
Usually, Germany would wake up when he heard his door softly close, but he wouldn't give any indication to being awake because he knew that on nights after Italy had that dream he wouldn't want to talk about it. Germany didn't even know what the dream was about, but he knew it had to be bad. One time he tried to ask about it and all he got was another wave of tears and a head shake. He didn't ask again. If Italy wouldn't talk about it, then it must have been really bad because usually his energetic friend would share everything with him.
Germany would lay still and let his friend cry into his back until he would eventually fall asleep. Then, and only after he was completely sure that Italy was asleep, he would slowly turn and wrap his arms around his friend. Italy would snuggle unconsciously into his embrace and Germany would blush and fight the urge to shove him away. If he couldn't even comfort Italy when he was awake then he would do the best he could while he was asleep.
The blonde would just lay like that for a while, relishing the feeling of his friend sleeping peacefully in his arms while puffing out warm breath on his skin. Sometimes Italy would stir in his arms and start whimpering, traces of the nightmare still in his mind, and Germany would place a comforting kiss on his temple and pull the brunette closer until he calmed down. And after a while, Germany would close his eyes and slowly drift off to sleep, dreaming that he had the courage to hold Italy when he was awake.
What he didn't know, was that as he slept, Italy would open his amber eyes and look up Germany's normally stoic face that had relaxed while he slept, and give him a small smile, before tilting his face up and lightly kissing the blonde on the cheek. Then he would smile again and snuggle into Germany's strong chest before drifting off to sleep along with his friend.
Germany may not have been the type to openly show affection, but that was okay with Italy, because in the dark hours of the night he knew that his friend truly cared for him.