"Son," says Sarek, handing Spock a datachip. "You should read this book."
Spock looks at the label, a warm, sandy color. The silhouette is of a man and a woman attached at the head, but the proportions are wrong: too short, too heavy, too…human. "The Joy of Sex, twenty-seventh edition," he reads, then looks at his father. "What utility does this text have for me?" Like most Vulcan boys, he had received an explanation of the basic cycle of his species' reproduction on the day of his betrothal at the age of seven. The mindmeld had been brief but thorough. It was made clear to him then that he would not be in a mental state to be guided by prior instruction in right behavior.
"I expect that T'Pring will be your bondmate, and, in that case, the book will provide some small insight into the minds of humans, which are very curious. On the other hand, I had expected that my only bondmate would be your brother's mother, and that was not the case." Sarek looks away from Spock then, the direction of his eyes indicating a thorough survey of Spock's quarters.
The silence extends for a longer than average conversational pause, but Spock says nothing. He does not know the primary benefit his father expects him to derive from this text.
"Your hormone profile from your last medical scan, did you review it?" asks Sarek.
Spock knows better than to think that the topic of conversation has changed. His father has cultivated a habit of multi-pronged attack from his diplomatic work, but he never has a single conversation about more than one thing, not if he can help it. And he can help it with his family. "As always, Father, I review my medical records after each observational visit. Readings were consistent with past scans." Consistency is the most favorable outcome. There is no Vulcan-Human hybrid 'average'; Spock is all of the available data.
"Your hormone profile shows a marked increase in plak hormone, Spock."
"My levels of plak hormone have always been lower than normal for male Vulcans of my age group, Father. I am closely monitoring my endocrine system for its effects, but this may merely signal the onset of puberty."
"Yes, I expect that it is the onset of puberty." His eyes snap back to meet Spock's.
Spock raises an eyebrow at his father to signal a lack of comprehension. What is there to get excited about? Spock is twenty, a little old for the onset of puberty in a human, a little young for a Vulcan.
Sarek raises an eyebrow in return. "While your physiology is generally that of a Vulcan, you do sometimes react more humanly than anticipated."
Abruptly, Spock realizes where Sarek is going with all of this. Spock recalls his brief fascination with Earth popular culture when he was eight; he read a great deal about the sexual exploits of humans of all ages, but particularly those of adolescents, who were biologically compelled to explore their bodies with one another. "I have not experienced erotic dreams, spontaneous erections, or nocturnal emissions, Father. I believe that my reproductive biology is largely Vulcan in nature."
"And yet, my son, we cannot predict that all of your reproductive partners will be Vulcan in nature."
Spock says nothing. He's lost, again, and too confused to formulate an appropriate question.
Sarek stares intensely into Spock's eyes, as if attempting to communicate telepathically without touch. "The human female reproductive cycle is approximately 28-36 days," he says, finally.
All four of Spock's eyelids blink without his conscious decision to do so. "Even the most intense biological stressor reduces a Vulcan male reproductive cycle to approximately 200 days," he responds. He doesn't feel the need to add that he's not planning to gorge in a cold room while exercising himself into a constant hypnagogic state in order to produce erections outside the normal pon farr cycle.
Sarek shrugs, hands clasped in front of his torso in the stiff little movement he has copied from his human staff. "Because sex is a recreational pursuit for humans, they have catalogued a large number of variant activities which produce satisfactory results."
The conditioning received in childhood via mindmeld is quite strong. Spock is unable to ask directly about his father's sexual practices, but he can grab Sarek's hand at the secondary mindmeld point.
He surprises both himself and his father when he takes Sarek down with a hard right jab.
Sarek stays on the floor, but covers his injured eye with his hand. "Why did you attack me?"
"How can you do those things to my mother?" Spock grits out, eyes closed, trying to unsee the undignified arrangements of his parents' bodies upon one another.
"So I wouldn't leave him for someone who can get it up more often than every seven years, of course. Humans like sex, Spock."
Spock looks up to see his mother standing in his doorway, frowning at him and his father both. He feels shame at his emotional reaction, his physical action.
"I told you to let me talk to Spock about this," she says to her husband. She sticks her right hand out to him. Sarek rises without touching her.
"You have never fully appreciated the strength of the related taboos," says Sarek.
She waves at him dismissively. "Oh, I appreciate it alright. I just think it's ridiculous, illogical, and puritan."
Spock frowns. "There is no religious significance to the—."
"That's not the point, Spock." She frowns back at him. And then she bends down to pick up the datachip and gives it back to him, careful not to touch his hands.
"What is the point, mother?"
"Look, T'Pring's father has been making noises about breaking your bond with her ever since it was made. If your adolescence becomes more human in nature, he probably will. Or, maybe you and T'Pring will try a mating cycle and divorce. Maybe when we go to Texas next summer one of your cousins will take you out behind a barn. Whatever. I just want you to be prepared in case sex with a human comes up, okay?"
Spock knows that he will never, ever do to anyone for whom he has any respect anything like what he glimpsed in his father's mind. It was animalistic and repulsive. He nods anyway, because he respects Amanda Grayson, even if she does things like that.
"Spock," says his mother, shaking her head at him, "promise me you'll read it before you recycle the datachip."
"I promise, Mother," he says. His PADD is on the table where he was studying before his father interrupted. He puts the chip in the reader slot, and, once again, nods his acknowledgement.