After successfully completing the mission assigned by the Hokage, Kakashi, Shikamaru had felt lazy enough to return to his apartment, so he opted to stay in yours because it was the closest to the Hokage's office.
"Fuck, what a drag..." Shikamaru muttered and huffed, plopping down on your couch. "I thought with the end of the war the missions were going to be reduced, but no." As usual, he was complaining about the complexity of recent missions and the physical exertion involved.
He watched you through his hooded eyes and followed your every move. He had been feeling things for you for a while now, and most of those feelings had been amplified and transformed with the onset of puberty in his adolescence. And now, in his adulthood, he knew that you wanted to push those boundaries as much as he did.
He had noticed it in your body language, and he had also been very obvious - approaching your body from behind when you didn't realize it, pretending that that-important-thing must have been whispered in your ear so you could hear it better, etc.
"Can I stay the night? I'm too lazy to go back to my apartment." He asked you, his voice groggy, as if he had taken a long nap. He knew you'd tease him because of his constant need for rest, but he didn't care. If it gave him a chance to be near you, he would.
Lately he was behaving strangely around you and stirring uncomfortably, but today he seemed much calmer, as if he was ready to make a move on you. Shikamaru was an enigma - and presumably that was perhaps due to his intelligence.
He ran a hand through his tied hair and his eyes met yours again. He watched you for a few seconds, as if he wanted to decipher you or the thoughts that lurked in your head. Finally his gaze fell back to his lap to search for a cigarette and lighter inside his pants pockets. He didn't know if that gesture was going to bother you, but he allowed himself to relax a little around you anyway and light the cigarette for a puff.