He watched it happen.
The Sheriff had never really thought of Stiles as stupid. An unfocused, vibrating, babbling baboon at times, but never stupid.
He knew his boy was smart – good grades in the midst of supernatural chaos were proof of that. But it had never really hit home until his son started hanging out with Lydia.
Because Lydia was smart. He'd only known this because Stiles had told him, but he'd honestly thought the love struck boy was exaggerating.
He was proved wrong, when the detective duo that was Stiles and Lydia, time and time again put their heads together to solve that week's supernatural murder mystery.
In retrospect, the reason Stiles brilliance suddenly came as a surprise, was probably because Stiles usual company was Scott, who didn't exactly inspire the most philosophical, ground-breaking conversation at the best of times.
It had started with debates on the supernatural, discussions about research, myth and legends, strategic advantages and weaknesses and the Sheriff had wisely continued through to the kitchen. He´d been happy when he discovered Stiles had made a new friend, even if the reasons for their get-togethers were, more often than not, life-threatening.
That had suddenly changed, though, and John couldn't pinpoint when it had happened. One day he got home and walked in on a discussion on Mac vs. PC. Two days later, it was a discussion on genetically modified organisms. Then it was euthanasia, then pollution, then Europe, then stereotypes and so on.
He was a little worried when the topic of whether or not drone attacks against specific targets were a necessary part of modern warfare came up. He thought it was hilarious when they started a discussion on marriage and raising children - that one lasted for days. He'd thought it was something they had to work on for school. It wasn't until he talked to Scott, that he realized it simply was Stiles and Lydia's version of relaxing, stimulating conversation.
It seemed to thrill Stiles, and he suspected Lydia as well, to have someone to challenge them intellectually. They hardly ever noticed when he got back home from work, Stiles pacing and gesturing, and Lydia on the couch, listening attentively – a rare thing for anyone to do, when Stiles got talking – and arguing firmly when she disagreed.
Lydia started staying for dinner, and John could honestly say he enjoyed the extra company, even if he didn't understand half of the conversations between the two young adults. He liked Lydia, and wondered if she still was in love with someone else.
He doubted it though.
Of course, once in a while, they disagreed. He'd been relaxing with a beer, watching a football game and enjoying himself, when Lydia suddenly came thundering down the stairs, his son chasing after her. He doubted they noticed him and when Stiles had pulled her to a stop halfway down and they'd ended up one step apart, looking into each other's eyes, both faces flushed and whatever argument the boy had been making had died on his lips.
After a minute of tense silence, that John had felt every second of, he saw, more than heard, his son whisper something intensely, which had Lydia swallow and nod, as if that was the most compelling argument she'd ever heard and it suddenly had John thinking that he should not be watching this, and should he have another talk with Stiles?
After that, they seemed to be closer, but as far as he could tell, they weren't together. Suddenly it involved a lot a casual touching, surprisingly initiated by Lydia most of the time and that evolved into cuddling while watching movies, cooking together (they liked to experiment and the Sheriff knew Stiles was a good cook, but along with Lydia, they were eating stuff he couldn't even pronounce, but tasted heavenly), and imagine his surprise when Lydia talked Stiles into going running.
He likes to think he made it happen. Indirectly, of course.
John likes to think he handled things perfectly, when Lydia came down the stairs, walked into the kitchen and sat down with a frustrated huff and exclaimed, "I don't want him to get hurt."
John was pretty sure Stiles hadn't been home in a few hours, so what Lydia was doing here and how she got in, escapes him. None the less, he managed to give her an impression of a tuna fish, which apparently prompted her to continue.
"I don't want to get hurt either. I should play it safe, right? That's what I was doing with Aidan. I was safe."
Wasn't Aidan one of the ex-evil Alphas?
"Emotionally safe, I mean," she continues as if she read his mind, "But he was boring."
"Well-" he finally utters, but his input was obviously not needed.
"- I just don't want to be the girl that is sitting at home, worrying and waiting. And he runs towards trouble, you know that, right?"
John knew that very well. But let's be fair here, "Don't you usually run right after him?"
Lydia closed her open mouth and twirled a piece of hair around her fingers nervously. She narrowed her eyes at him, "I.. Well, someone has to save him when he gets into trouble. He needs that."
"Then he needs you. Right?"
John congratulated himself later that he'd managed to make Lydia Martin speechless, something he'd rarely ever only seen his son be able to do. The girl stood from her chair with a determined look and clenching fists.
"Just so we're clear," John hurried before she could run off, "Should I be worried? Are you guys in danger?"
"Oh, no, we've got it covered," she said on her way out the door.
John also liked to think he handled the Stiles-version of that conversation pretty well.
"What the hell does emotionally safe mean?!"
"That she cares about you a lot and would be devastated if she lost you? That being with someone she aren't emotionally involved with, is easier, more convenient and maybe that she's scared she'll get hurt if she allows herself to love someone she's too likely to lose?"
".. Oh."
"Yeah, oh."
"Isn't it worth it, though? Was it worth it with Mom?"
John had never been more certain of anything in his life and he made sure to look his son right in his eyes, when he said, "Yes."
When he witnessed them a week later, cuddling closer than ever, he smiled and his smile turned to a grin when he saw their eyes meet and Lydia lean up to kiss Stiles – and then he hurriedly left the room.