Based on a Tweet I saw from SadSakuSmile on Twitter of a YouTube comment (I think it is) from lila
Sasuke type of guy to wake up Sakura to tell her he is going to sleep
This is just my take on it^^
The last time he had company in his house, his parents were alive and his mother would always tuck him in bed. Even when he told her, he was a big boy and could do it himself. She would reply that he would always be her baby.
So it was weird to have Sakura in his house, even if they have been together for a while. There's a difference between being together and sleeping in the same bed as someone.
Although by the time he got upstairs, Sakura had fallen asleep.
Sasuke lifted the blanket gently nudging his girlfriend.
"Sakura."
"Hmm?" Rubbing the sleep out of her eyes, the kunoichi glanced over her shoulder at him.
"What's up?"
"I'm going to sleep now."
Sakura blinked, unsure she heard him correctly.
"Uh, okay?"
She wasn't sure why that was necessary, he could easily sneak in the bed with her.
However, when his arm snuck around her waist tucking his head against her neck, Sakura understood.
"Is this okay?"
"Yeah," she melted snuggling against him. This was more than okay.
I just think this would be a cute headcanon.