"Dad," Ian starts as he walks through the door. "What does homosexual mean?"

Sherlock spits and chokes on the tea in his mouth. He chuckles as he regains his breath and wipes his mouth. Ian stares at him with wide, curious eyes. "What makes you ask?"

"Some kids said it at school. It sounded bad, like a disease. What is it?"

Sherlock laughs as he walks past Ian and into the living room. "Ask Dad when he gets home."

John walks through the door and is too busy fixing dinner to stop and answer Ian's questions. Once they're sitting and eating, almost done, Ian asks John.

"Dad, what does homosexual mean?"

Sherlock grins and stands, chuckling the way to the sink and laughing as he walks out of the kitchen.

"Wh-why do you ask?" John asks. It's not that he's uncomfortable by the topic, he just assumed up until now that Ian would never ask what that meant. Not that Ian should know, that Ian should know the technical term for his fathers.

"Some kids were saying it to another kid at school. They made it sound bad. Like a disease. Is that boy sick, Dad?"

John vigorously shakes his head. "It's not an illness, and it's not bad at all. Ok?"

Ian nods. "What is it?"

John sighs. "Well, uhm, it's when a boy, or a girl, is sexually attracted to other boys and girls. Well," John fumbles over the explanation. "It's when boys like boys and girls like girls."

Ian nods in understanding. "Like you and Dad then?"

John nods. "Yeah. Like Dad and I. He's attracted to me, and I'm attracted to him. And we're both boys."

Ian nods again. "But…sometimes…" Ian trails off in thought.

"Sometimes, what?"

"Sometimes you look at girls the way you look at Dad."

Sherlock suddenly appears in the doorway of the kitchen. He crosses his arms and leans against the door frame. "And how is that, Ian?" he asks, staring at John and raising an eyebrow.

John grows hot under Sherlock's intense stare.

"Sometimes, Dad, you look at lady's chests and arses."

"Don't say arse," John warns.

"Erm," Ian thinks, "Bum, then. Yesterday at the shop, you were talking to that woman and you didn't really look at her face."

Sherlock steps closer to the table. "Oh really?" he asks, still staring at John.

John glances from Ian to Sherlock, then back to Ian. "Well, Ian…uhm…" John licks his lips in thought. "Sometimes men can be attracted to both men and women, and that's ok, too."

"But you don't look at other men like that," Ian says.

"Yes," John says, "That's because I grew up liking women, but then I met Dad and fell in love with him."

Having had the sex talk last year, Ian's not shy about talking about this stuff with his dad's. "But you want to have sex with ladies?" he asks.

"No, no!" John defends. "I don't. I'm just saying, it's ok for boys to like girls and boys, and it's ok for girls to like boys and girls. And it's ok to grow up one way and fall in love with someone of the other gender. Ok?"

Ian nods. "I think I've got it."

"Good," John says, taking a deep breath and sitting back in his chair. "Those boys were not being nice when they were saying things to the other boy. It's not a disease, it's not wrong."

Ian nods again. Then he looks up at John with fearful eyes. "Is it ok for me to like girls?"

"Yes, of course! You can like whoever you want!" John says. He points a finger at Ian. "But no kissing or girlfriends until you're older, understand?"

Ian nods. "Ok, Dad."

"Any more questions?"

Ian thinks. "I've got one."

"Go ahead, son."

"Well," Ian bites his lip. "When you were younger you liked girls?"

John nods. "Yes."

Ian looks at Sherlock. "Did you like girls, too, Dad? Or did you always like boys?"

Sherlock takes a seat at the table once again. "Well, I didn't really like anybody growing up."

"You didn't?"

"No. Well, I liked my tutor when I was young, about your age. He was very smart and I looked up to him, so I wanted to marry him."

"What happened?"

"He was much older than me, he was nearly eighteen. He started to date Uncle Mycroft, and he broke Mycroft's heart. My mother fired him and I threw rocks at him."

Ian chuckles. "You did?"

"Yes. I didn't think it was right he hurt Uncle Mycroft."

"That's funny, Dad!" Ian laughs.

Sherlock grins at his son's laughter.

When Ian calms down, he resumes his questions. "When did you start to like people?" he asks.

Sherlock bashfully looks at John. "When I met your Dad."

John smiles down at his plate.

"What happened?" Ian asks.

Sherlock shrugs. "I don't know. I just knew I liked Dad. He's funny, smart, loyal, brave," Sherlock grabs John's hand. "And I knew that I loved him."

Ian nods. "So you never liked girls?"

"Not really," Sherlock replies. "I tried to date a few, but I was never interested in them."

Ian nods in understanding. "So, you didn't like anyone. And Dad liked girls. And Uncle Mycroft? Did he always like boys?"

Sherlock nods. "Yeah, he did."

Ian looks at John. "What about Aunt Harry?"

John nods, too. "She always liked girls."

"Huh," Ian mutters. "Is, erm, being homosexual common in families?"

"I guess it's not uncommon," John says. "It just…I guess it just depends on how someone is born."

Ian nods in understanding. "Ok. I get it all now."

"Good," John says. "If you have more questions like that, don't be afraid to ask, ok?"

Ian nods and stands from the table. "Ok, Dad. Thanks."

Ian disappears up the stairs to his room and Sherlock looks at John. "You handled that well," he says.

"How was I supposed to handle it?" John asks.

"No other way," Sherlock says, smiling. "Though I do find it funny that he asked us what homosexual means."

John smiles. "It's not like he should know. It's not like he has two parents that tell him it's wrong or something."

Sherlock leans closer to John. "Our sons have two daddies who love each other very much."

"Mmmm," John hums, leaning in to kiss Sherlock.

Sherlock leans closer to John, his lips brush his husband's. "He's got one dad who is going to sleep on the couch tonight," Sherlock says, quickly standing.

John frowns. "Sherlock! It didn't mean anything!" John calls, following Sherlock into the living room.