The harvest-time festival was held during a time when they were both out on missions, unfortunately, and couldn't be there. They missed Hinata spraining an ankle when she went dancing with Naruto, Sasuke bringing some girl home and getting caught by Fugaku, and the main events of the festival, but were present for the closing fireworks.
Shinobi were not allowed to feel love, or any of the gentler emotions which the Hermit Sannin wrote so frivolously about. They were not allowed the luxury of humanity, but when they did becoming human, they formed bonds that took apathy and the chill hand of evil to break.
It had started with a perfectly innocent, chaste kiss, which was all Neji had ever allowed in public. The Hyuugas had ground fear of the gossip mill into all their children, and Neji was no exception. Until Itachi had pointed out that there was nothing nearby and no one around them to see, their kisses had remained infuriatingly innocent.
Half under him, Neji made a little noise in his throat. His lips were kiss-reddened and swollen, glistening invitingly when Neji licked them. Itachi touched them with a finger, then kissed him furiously again. He ran the tip of his tongue over the seam of the younger man's lips and they parted willingly, Itachi's tongue delving in to finally taste him. He sighed contentedly, drinking from Neji's lips as though the sweetness he found there was the elixir of life and he was a dying man.
He had a hand on Neji's belly, feeling the play of muscles there as the other would stretch to meet his mouth more fully. Itachi's kisses moved from Neji's lips along his jaw to his throat, feeling the swift pulse under the skin and smirking a little. Neji's hands on his back flexed a little, and Itachi bit lightly, at the same time sliding his hand down to the top of his partner's pants.
He felt Neji twitch away a little and moved his hand and head away, looking down at Neji's face. In lust-glazed eyes he saw the reflection of the fireworks overhead, glittering like the threads of color in a polished opal. The thumb of his other hand rubbed Neji's cheek.
"Do you trust me, Neji?"
The pause seemed as long as a lifetime. "I trust you."
Itachi's hand moved back down, brushing sensitive fingers over even more sensitive skin, and hidden by the booming fireworks, Neji moaned. The Uchiha drank up every one he coaxed out of that lovely throat, and before long, he realized that he was moaning too as Neji's hands moved and helped him. They were more skilled than he had thought.
The fireworks high above were mirrored below.