They never did anything special for Valentine's Day, through all of the years they'd known each other and the few they'd actually been lovers? boyfriends? together. They never felt it was necessary, and besides, Valentine's Day is technically the day specifically for girls. They never did anything for White Day, either, but that wasn't the point.
The point was that neither of them had ever been romantic in their relationship, which was why Mikado was so surprised when on February 14th, Izaya got up from his computer, stretched, and said, "We should go out to celebrate the holiday. I'll pay."
There was a slightly stunned silence before Mikado replied, "I'm sorry, what?"
Izaya gave him a slightly amused look. "I said that we should-"
"I should rephrase the question," Mikado interrupted. "Why?" Mikado hadn't lost his ability to stay under the radar by seeming kind and innocent, but the years had allowed him to be confident enough that his true personality surfaced more and more often. Izaya adored him all the more for it.
"I thought it would be a nice change of pace," he lied. Mikado sent him a look that showed Izaya exactly what he thought of that statement, and Izaya cursed the day that Mikado had gotten close enough to read him like an open book.
"I may have been talking with my sisters," he began, hesitating because his relationship with his siblings was embarrassing and he hated admitting how fond he was of his demonic twin sisters.
"Oh, dear," Mikado murmured in amusement. He wasn't quite sure how, but after the three Orihara siblings got in contact after years of silence, they had grown closer than they had when actually living near each other. An unfortunate side effect was that Izaya had begun taking the things they talked about as challenges and tried to one-up them at every turn.
Mikado hadn't told Izaya this, but from what he heard from Masaomi and Sonohara-san (he had never quite gotten out of the habit of calling her that, even during their failed dating attempt) in their frequent emails, the twins were doing the same thing in Ikebukuro, where Masaomi, Sonohara-san, and Saki-san still lived. He and Masaomi had taken to betting on what the next grand gesture the siblings would do next while Sonohara-san played the impartial judge.
Mikado always won. After all, he did live in close quarters with one of them, although neither Masaomi nor Sonohara-san liked to acknowledge that fact.
When Izaya didn't say anything more, Mikado asked, "What did they do this time?"
Izaya gave him a sour look before continuing, "Apparently they have finally gotten Aoba-kun to take them both on a genuine date for Valentine's Day, and they emailed me about their 'great achievement' or whatever it was they were crowing about. Honestly, Mikado-kun, why did you convince me to get in contact with them again?"
"I thought you should at keep contact with one of your family members. One of us should, anyway."
There was a slightly awkward pause after that. Izaya knew that Mikado was sensitive about his estrangement with his parents after his refusal to return to his hometown after high school, and Izaya wasn't willing to pick at that particular scab. It wasn't that he was afraid of poking old wounds (he and Mikado often did that to get the upper hand in their frequent games of manipulation); it was that whenever he did so, Mikado would bring up his mostly one-sided friendship with Shinra, how the two of them hadn't talked since Izaya's defeat at the hands of Shizuo and his subsequent escape from Ikebukuro.
They had enough respect for each other not to use things like that against the other.
"Well, I can't have you losing against your sisters," Mikado said, giving Izaya a teasing smile. "Just this once, I suppose. It would be nice to have 'a change of pace,' as you so eloquently put it."
He also wasn't going to turn down a free dinner at what he suspected would be a high-end restaurant, some place that Aoba-kun, Mairu, and Kururi put together wouldn't be able to afford.
As he and Izaya walked into the city they controlled from the shadows, Mikado thought of how grateful he was that he had taken Izaya up on that offer years ago.