-When he's sleepy, he acts like a baby. But for real. I mean he's not even speaking, 'cause "it takes so much energy". He is just existing, nothing more.
-If you sit down beside him, he lays his head on your shoulder. (And you can't move) No matter what you do, he's not gonna get up.
-If you say something to him, maybe he's just not hearing it. In his thoughts he is already sleeping.
-When it really comes to a sleep, he wants to sleep with you (ofc).
-If he's tired or sleepy, no matter what position you are in, he is going to fall asleep.
-If he's not really tired or sleepy, he likes to hug you from behind and bury his face in your hair. Or laying down facing each other, and talking while holding hands.
-Sometimes (mostly when he is VERY tired or sick) he just likes to cuddle up to your chest, and listen to your heartbeat.
-If he wakes up before you, he likes to watch you sleeping. I mean you are cute when you sleep.
-If you hug or cuddle while sleeping and he wakes up first, he is not moving until you wake up. He's not wanting to wake you.
-Sometimes he has nightmares about you two falling apart, or you dying. It really freaks him out, but everything gets back to good when you smile at him lovingly.
-He hates getting out of the bed.
"Just one more minute" like a hundred times.
And last but not least:
-He just Can't sleep without you. More likely he is falling asleep very hard (and it takes long) if he can't feel you beside him. He needs your calming aura and your sweet scent.
(That's all I wanted now. If you have anything else that should be here, tell me.)