Disclaimer: If I owned Star Trek, I'm sure someone would have let me know by now.
AN: Written for a 5 Times prompt. 5 Times Spock saw his father loving his mother. :3 Broken up into chapters because it made sense to.
Spock didn't know his father could play any musical instruments. In his six years he'd never heard even the slightest indication of music from his father's study, nor the lightest lyrical lilt in his even, mathematical tones. Ergo, it was very strange when he came downstairs to borrow his mother's favorite afghan from her study and he heard light, immaterial tones resounding from behind his father's door. His original task was immediately forgotten as the slow, twining notes slipped across the warm stone flooring. He walked carefully, quietly, and with unconscious, unpracticed, childish stealth until he was just close enough to peer through the three millimeter gap between the threshold and the door itself.
His mother was reclining, the dark robes his father had been wearing that morning were draped across her shoulders, and there was a gentle, easy smile across her face. His father, clad in his long-sleeved shirt and crisp-cut pants, stood less than a meter from her. His eyes were closed serenely and his fingers curled around the neck of an instrument Spock didn't recognize. His father drew a long, slim bow across the strings and his fingers ran along the strings in uneven, mechanical motions.
The song he played was not Vulcan. Rather, it sounded like the music his mother listened to on the occasions she rose before dawn. As the strings and the bow contacted, his father drew languid, warm notes from the instrument. He pulled the notes slowly, in carefully controlled time, and Spock watched as his mother's eyes slipped closed for several seconds.
The song was simple, a repetition of a single chorus with very little alteration, and it was over fairly swiftly. His father drew several long, somber, tender notes and lowered the bow to his side. His mother's eyes flitted open and her hands came together genially. She applauded him softly, her sweet smile reaching up into her eyes as he lowered the instrument and placed it on his desk.
"You don't play the violin," she accused and her voice sounded strained. Spock panicked momentarily as her eyes watered—the constriction of her throat and the redness across her face could indicate peril. "You learned Träumerei just for this?"
"You indicated a preference for this particular composition," his father's voice was even and unconcerned as his mother stood and allowed his robes to fall to the ground. His dark eyes followed her as she crossed the short distance to him."Was I incorrect in this course of action?"
"No," she whispered and placed a gentle kiss against his lips. She wrapped her arms beneath his and leaned her head on his chest as she embraced him. One of his hands came to settle at the small of her back and, to Spock's confusion, his father's lips lilted upward unconsciously.
"Spock," his father's voice resounded in the peaceful silence and Spock started slightly, "You should return to your chambers and sleep." Spock didn't hear his mother's gentle, teasing reprimand or his Father's soft retort as he darted straight back to his room.