The third time Severus almost lost composure:
It was with a long-suffering sigh that Severus approached yet another shouting match between Gryffindor's Golden Brat and Slytherin's Silver Prince on the seventh floor. One of these days, one of them was going to remember they had wands, and someone was going to be seriously hurt. He didn't blame Potter for being suspicious of either of them, he would be as well, but why couldn't the brat leave well enough alone? Severus had enough to deal with, without trying to corral two broiling teens at the center of a war, for Merlin's sake.
He paused around the corner of the corridor, trying to settle his own racing heart before he confronted the pair. It was an annoying new aspect to his hectic days and sleepless nights, that he had started becoming entirely unsettled when faced with Potter, and he needed to get it under control. He wasn't a fool, he recognized the symptoms, but as a double spy simultaneously trying to teach reckless children one of the most dangerous arts, he really couldn't afford this distraction.
It was unclear when it had started, or what had been the catalyst. Something innocuous, most likely. The sun hitting those striking green eyes the right way, perhaps, or the way Potter's whole body thrummed with untamed magic when he got pissed… whatever it was, it was leaving Severus in an unfavorable state. For a Master Occlumens, it was shameful how often his thoughts had begun to wander to the brat of late. It was clear he needed to stay away from Potter, not that the Gryffindor was making it easy by any means.
After the last meeting with the Dark Lord… Well, thank Merlin he had ample memories to cover his thoughts about the teen. Slughorn's recent gushing about his Potions prowess had proved invaluable. The Dark Lord had been distracted enough by it, at least, and it served to prove that he'd never given Potter any slack. It was killing him not to know the cause behind Potter's sudden interest in his previous course, but at least it might save him… until he had to die. Now if only he could get his heart to accept what Albus had told him about the young man's fate, maybe he wouldn't have so many restless nights. He almost missed having Potter's musical references being the only personable thoughts he'd had of him.
"Merlin, Potter! Wonder what Weasley would think about you stalking me instead of her? I knew I had a pretty face, but-!"
"Your 'pretty face' is going to hell!"
Severus had never been more grateful to see his old Head of House as he did in that moment. Slughorn was coming from the other end of the corridor towards the arguing duo as Severus leaned heavily against the wall, trying not to collapse. How the hell could he face Potter if he kept being such a musically inept dolt? Turning, stifling his laughter behind a cough, he found himself once again retreating to his dungeons where he could, hopefully, drown out the music in his head before he had to face the Dark Lord again. The snake-faced git never had appreciated Muggle music, he doubted that had changed since his resurrection.