"Sherlock, will you please tell your son that if he insists upon bringing nicked body parts to school and then setting them on fire in the chemistry lab, he will be looking at the introduction of a private tutor on his grandmother's estate in the near future."
"My son?" Sherlock frowned at his husband and son. "Why's it he's always 'my son' when he gets in trouble?"
"Because I've never been asked to leave a primary school. Six times in one calendar year," John said, glaring. "This is clearly your area."
Sherlock narrowed his eyes on the boy, who stood unflinching beneath his father's steely gaze. "Hamish?"
"Yes, Father?"
"I believe we discussed the proper environs for conducting experiments, did we not?"
"We did, Father. On several occasions."
Sherlock pursed his lips. "Yes, several. And what was the outcome of these conversations?"
"Experiments are never to be conducted at school, only at home, and under the direction of either you, Daddy, or Mummy." Hamish waited.
Sherlock's eyebrow rose.
"Uncle Mycroft's things, credit report, and his person are never to be used as a subject," the corners of the boy's cupid's bow turned up, "again."
"Go on."
"I am never to be allowed unsupervised when visiting Mummy at her work, because lying in wait in the morgue drawers to judge reactions upon realizing a body previously thought to be dead is, in fact, not dead, is not an experiment; it's just rude."
"And?"
"Things in locked cabinets are locked away for a reason; it should not be considered a personal challenge to unlock them. And just because I unlock them, because I always unlock them, does not mean the contents now belong to me." The little boy's eyes narrowed in a manner just like Sherlock's.
"Finally?"
Hamish sighed and rolled his eyes. "Boredom is no excuse for destruction."
"And having recalled all of this, Hamish Watson-Holmes, what do you have to say for yourself?"
"Nothing, Father. The facts speak for themselves. Although, I will say in my defense, someone moved my Bunsen burner. The drapes never would have caught fire otherwise. And who puts drapes in a chemistry lab? Honestly."
John rolled his eyes and sighed heavily. "To your room, Hamish. We'll call you for dinner."
Hamish looked sheepishly at his other parent. "Yes, Daddy."
John's eyes turned to Sherlock as the boy crept up the stairs. "I'm still blaming you for this, you know."
"I think I can live with that," Sherlock replied.
John sank down onto the sofa next to his husband, threw back his head and sighed again. "Oh, Sherlock. How did we get here?"