No, that's not right; he's a genius, after all. He knows he's more than half in love with her.
And if he weren't so damn bent on keeping things simple, he'd tell her.
Tell her she's stupid for wanting someone as unreachable for her as she is for him. Hypocrisy was never his style before; neither was jealousy.
Tell her the clouds are half his metaphor for her: his precious companions, whom he could never touch, never feel, no matter how badly he wants to.
Tell her the half-annoyed look on his face when she starts yelling at him means just that: he's half annoyed. He's also half content.
Tell her laziness is half a means to an end. After all, she always comes screaming when he practices it. And he loves that part. She comes.
Tell her -
"Nara Shikamaru! What the hell are you still doing here? We're supposed to be meeting Asuma-sensei in two minutes, and you're still lying here staring at the clouds! Get off your lazy ass right now!"
But he gets up immediately anyway.
That's his lazy way of telling her – he's more than half in love with her.
And he's barely admitting half the reasons why.