It wasn't unusual for Sonic to occasionally have trouble sleeping. For hours he'd toss and turn in the sheets trying to get comfortable, until the twenty-one year old would eventually give up and blankly stare at the ceiling hoping sleep would come to him soon.
This would have been just fine... if he was alone in the bed. But for his poor bedmate, anytime Sonic couldn't sleep, he couldn't as well. And Mario knew it wasn't intentional but the violent movement next to him and the sheets moving every five minutes made it really difficult for him to sleep as well. Which was an issue as being the lone doctor in the Smash Mansion required focus and if he was tired on the job...
Mario had been trying to sleep for the past hour but Sonic was having a bad time on this particular night. Even in the dark Mario could see that Sonic's silhouette was tense, most likely a result of knowing he had important matches all throughout the day. He currently had his back to Mario, and without giving it much thought Mario wrapped an arm around his partner while he gently stroked the long quills with his free hand.
He felt Sonic relax almost immediately and he continued his motions, hoping the repetition would ease Sonic into slumber. Pausing for a moment, he began to quietly sing an Italian lullaby, one his mother used to sing to him and Luigi when they were children. Even though Mario knew his singing voice wasn't the best (there was a reason Sonic didn't want to sing duets with him) it seemed to be doing the trick as he could hear Sonic's breathing had slowed and he was no longer fidgeting. After a few minutes Mario wrapped both his arms around Sonic's torso and lightly kissed his shoulder.
"Buona notte, amore mio."